National Academies Press: OpenBook
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

Assessing the Use of
AGENT-BASED MODELS
for TOBACCO REGULATION

Committee on the Assessment of Agent-Based Models to Inform
Tobacco Product Regulation

Board on Population Health and Public Health Practice

Robert Wallace, Amy Geller, and V. Ayano Ogawa, Editors

INSTITUTE OF MEDICINE
               OF THE NATIONAL ACADEMIES

THE NATIONAL ACADEMIES PRESS

Washington, D.C.

www.nap.edu

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.

This study was supported by Contract/Grant No. HHSF22301031T between the National Academy of Sciences and the Department of Health and Human Services: Food and Drug Administration. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.

International Standard Book Number-13: 978-0-309-31722-1
International Standard Book Number-10: 0-309-31722-3

Additional copies of this workshop summary are available for sale from the National Academies Press, 500 Fifth Street, NW, Keck 360, Washington, DC 20001; (800) 624-6242 or (202) 334-3313; http://www.nap.edu.

For more information about the Institute of Medicine, visit the IOM home page at: www.iom.edu.

Copyright 2015 by the National Academy of Sciences. All rights reserved.

Printed in the United States of America

The serpent has been a symbol of long life, healing, and knowledge among almost all cultures and religions since the beginning of recorded history. The serpent adopted as a logotype by the Institute of Medicine is a relief carving from ancient Greece, now held by the Staatliche Museen in Berlin.

Suggested citation: IOM (Institute of Medicine). 2015. Assessing the use of agent-based models for tobacco regulation. Washington, DC: The National Academies Press.

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

Knowing is not enough; we must apply.
Willing is not enough; we must do.
”      

                                                —Goethe

image

INSTITUTE OF MEDICINE
              OF THE NATIONAL ACADEMIES

Advising the Nation. Improving Health.

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

THE NATIONAL ACADEMIES

Advisers to the Nation on Science, Engineering, and Medicine

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences.

The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. C. D. Mote, Jr., is president of the National Academy of Engineering.

The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Victor J. Dzau is president of the Institute of Medicine.

The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Ralph J. Cicerone and Dr. C. D. Mote, Jr., are chair and vice chair, respectively, of the National Research Council.

www.national-academies.org

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

COMMITTEE ON THE ASSESSMENT OF AGENT-BASED
MODELS TO INFORM TOBACCO PRODUCT REGULATION

ROBERT WALLACE (Chair), Irene Ensminger Stecher Professor of Epidemiology and Internal Medicine, Department of Epidemiology, University of Iowa

ELIZABETH BRUCH, Assistant Professor of Sociology and Complex Systems, Assistant Research Scientist, Population Studies Center, Department of Sociology, University of Michigan

KAREN GLANZ, George A. Weiss University Professor (Penn Integrates Knowledge [PIK] Professor), Professor of Epidemiology and Nursing, Perelman School of Medicine and School of Nursing, University of Pennsylvania

CARLOS ROBERTO JAÉN, Dr. and Mrs. James L. Holly Distinguished Professor and Chairman of Family and Community Medicine, and Professor of Epidemiology and Biostatistics, University of Texas Health Science Center, San Antonio

SCOTT J. LEISCHOW, Professor of Health Sciences Research, Mayo Clinic

DOUGLAS LUKE, Professor and Director, Center for Public Health Systems Science, George Warren Brown School of Social Work, Washington University in St. Louis

CHARLES F. MANSKI, Board of Trustees Professor in Economics, Department of Economics, Northwestern University

DAVID MENDEZ, Associate Professor, Health Management and Policy, School of Public Health, University of Michigan

NANCY A. RIGOTTI, Professor of Medicine, Harvard Medical School, Director of Tobacco Research and Treatment Center, Associate Chief, General Medicine Division, Massachusetts General Hospital

DAVID SHOHAM, Associate Professor, Department of Public Health, Loyola University Chicago

JODY SINDELAR, Professor of Public Health (Policy) and Economics, Department of Health Policy and Management, School of Public Health, Yale University

MELISSA STIGLER, Associate Professor, Division of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, University of Texas

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

Consultants

LAWRENCE E. BLUME, Goldwin Smith Professor of Economics, Cornell University

ROSS A. HAMMOND, Senior Fellow in Economic Studies, Brookings Institution

ALAN H. SANSTAD, Staff Scientist, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory

IOM Staff

AMY GELLER, Study Director

V. AYANO OGAWA, Research Associate

BETTINA RITTER, Research Assistant

ANNA MARTIN, Senior Program Assistant

DORIS ROMERO, Financial Associate

ROSE MARIE MARTINEZ, Senior Board Director, Board on Population Health and Public Health Practice

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

Reviewers

This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the National Research Council’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of this report:

DAMON M. CENTOLA, University of Pennsylvania

SEYMOUR S. COHEN, Marine Biological Laboratory

ANA V. DIEZ ROUX, Drexel University

STEVEN N. DURLAUF, University of Wisconsin–Madison

STEPHEN EUBANK, Virginia Polytechnic Institute and State University

SANTO FORTUNATO, Aalto University

DOROTHY HATSUKAMI, University of Minnesota, Minneapolis

LEE D. HOFFER, Case Western Reserve University

ELENA G. IRWIN, Ohio State University

PAULA M. LANTZ, George Washington University

DAVID LEVY, Georgetown University

SIDNEY REDNER, Boston University

Page viii Cite
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations, nor did they see the final draft of the report before its release. The review of this report was overseen by RONALD S. BROOKMEYER, University of California, Los Angeles, and ALFRED O. BERG, University of Washington. Appointed by the National Research Council and the Institute of Medicine, they were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

This page intentionally left blank.

Page xiii Cite
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

Acronyms and Abbreviations

ABM agent-based model, agent-based modeling
Add Health National Longitudinal Study of Adolescent Health
BRFSS Behavioral Risk Factor Surveillance System
CDC Centers for Disease Control and Prevention
CISNET Cancer Intervention and Surveillance Modeling Network
CTP Center for Tobacco Products
DPMP Drug Policy Modelling Program
EPA U.S. Environmental Protection Agency
FD&C Act Food, Drug, and Cosmetics Act
FDA U.S. Food and Drug Administration
HHS U.S. Department of Health and Human Services
IOM Institute of Medicine
NCI National Cancer Institute
NIH National Institutes of Health
NRC National Research Council
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
PATH Population Assessment of Tobacco and Health
PHEV Plug-in hybrid electric vehicle
RCT randomized controlled trial
SAMHSA Substance Abuse and Mental Health Services Administration
SnapDragon Social Network Analysis for Policy on Directed Graph Networks
SNL Sandia National Laboratories
Tobacco Control Act Family Smoking Prevention and Tobacco Control Act
TPSAC Tobacco Products Scientific Advisory Committee
TUS–CPS Tobacco Use Supplement of the Current Population Survey
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

Preface

Models are often used to represent complex systems. As such, they can be used to provide a framework for thinking through difficult problems, to help researchers understand factors within the complex system and their relations to specific events, to guide data collection efforts, and to identify research needs. Models are also useful for exploring policy and regulatory questions.

There is a long history of using models as one tool to guide policy making in a range of disciplines, including transportation, environmental health, energy, and health. One public health topic in which various modeling approaches have been used to address policy questions is tobacco control. Tobacco control models have been used to look at the impact of cigarette taxes, smoke-free ordinances, and smoking cessation programs. The Center for Tobacco Products (CTP) at the U.S. Food and Drug Administration (FDA) uses modeling to inform its regulatory decisions. In fact, two population models—SimSmoke and the Cancer Intervention and Surveillance Modeling Network, or CISNET, model—were used in a recent CTP-sponsored Institute of Medicine (IOM) report to study the impact of changing the minimum purchase age of tobacco products.1 Those models, along with insights gleaned from traditional statistical and epidemiological studies, helped inform that committee’s conclusions.

Although these models continue to be important in informing policy decisions by making it possible to project the impact of tobacco policies

_____________________

1IOM (Institute of Medicine). 2015. Public health implications of raising the minimum age of legal access to tobacco products. Washington, DC: The National Academies Press.

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

and interventions at the population level (aggregate models), the majority of these models do not consider interactions at the individual level or the heterogeneity of individuals, which can be important when examining some tobacco regulatory policies. One modeling approach that CTP is exploring to address such individual interactions is the use of agent-based models (ABMs). ABMs can elucidate interactions at the individual level and thus complement population models. Existing population-level tobacco control models have provided great insight into the effects of various tobacco policies, and multiple modeling approaches are needed—and will continue to be needed—for complex problems such as understanding the impact of tobacco regulation. The results of ABMs can also be used as inputs for population models. With that in mind, it should be noted that the recommendations in this report have no relevance for the type of modeling used in the recent 2015 IOM report noted above, which focused on projections based on population models.

Through an interagency agreement, CTP commissioned Sandia National Laboratories (SNL) to develop an ABM to explore certain tobacco policies under the jurisdiction of CTP. To that end, SNL is developing a model entitled Social Network Analysis for Policy on Directed Graph Networks (SnapDragon). Thus far, the model has been developed through an iterative process and as of July 2014 was in an intermediate stage of development. CTP asked IOM to evaluate SnapDragon in its current stage of development. The Committee on the Assessment of Agent-Based Models to Inform Tobacco Product Regulation was created to conduct that review, which is presented in this report. CTP also asked for advice on using ABMs in the future, which the committee addresses in this report. The developers of SnapDragon provided updates on the model up until July 31, 2014. In July 2014 and January 2015, draft descriptions of the committee’s technical understanding of the model2 were sent to SNL for technical review. In the lab’s January 2015 response, SNL described some updates that had been made to the model since the July 31, 2014, cutoff date and also provided information on some changes to the model that might be made in the future. However, the committee did not have an opportunity to examine any revisions to the model made after July 2014.

In addition to evaluating SnapDragon, the report offers guidance to CTP on developing and evaluating ABMs. It was beyond the scope of this report to develop specific guidance on exactly what policies or questions could be addressed using policy-relevant tobacco control ABMs. Furthermore, developing a core set of essential domains or attributes for policy-relevant

_____________________

2The correspondence and excerpts between the committee and SNL are available in the project public access file: https://www8.nationalacademies.org/cp/ManageRequest.aspx?key=49612.

Page xvii Cite
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

tobacco control models is a challenging venture that would vary depending on the intended purpose of the model; the time frame of this study did not allow the committee to fully explore this. In Chapter 2 the committee outlines the complex tobacco regulatory environment and the variables that need to be considered in the current regulatory environment. Each policy question to be addressed by FDA will require input from subject-matter experts as well as modeling experts to ensure that the relevant dynamics are captured in the model. This report also offers a number of issues for ABM modelers and model users to consider during model development, some important data considerations, and an evaluation framework that CTP can use in its future development of ABMs.

Acknowledgments

The committee wishes to thank the colleagues, organizations, and agencies that shared their expertise in the development of this report. Their contributions informed the committee and enhanced the quality of the report.

First, the committee thanks the Center for Tobacco Products of FDA for sponsoring the report and for bringing attention to the importance of developing models that can inform tobacco control policy. The committee expresses its deep appreciation for the SnapDragon model developers at SNL for their willingness to present the model, respond to the committee’s questions, and share their experience and thoughts on the model.

The committee thanks Lawrence Blume, Ross Hammond, and Alan Sanstad for writing commissioned papers that informed the committee on the varying views concerning ABM, the practice of and pitfalls associated with ABM, and lessons learned regarding the application of ABMs. These papers were critical to the committee’s deliberations.

The committee also thanks those individuals who volunteered their time and shared a wealth of information with the committee during our public meetings. Their perspectives provided valuable insights which informed the deliberations of the committee and, ultimately, the report. The meeting agendas provided in Appendix D include the names of all speakers. The committee would especially like to thank Margaret (Maggie) Eppstein of the University of Vermont and Allison Ritter and Pascal Perez of the Drug Policy Modelling Program based at the University of New South Wales in Australia for taking the time to describe the ABMs they had developed, and to answer questions from the committee and staff.

Finally, the committee expresses its gratitude to the IOM staff members who contributed to the production of this report, including study director Amy Geller, research associate V. Ayano Ogawa, research assistant Bettina Ritter, senior program assistant Anna Martin, and board director Rose Marie Martinez. Other staff members of the Board on Population Health

Page xviii Cite
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×

and Public Health Practice, including Hope Hare, Doris Romero, and Kathleen Stratton, provided important support as well. The committee is also thankful for Norman Grossblatt and Robert Pool for their editorial support as well as for the National Academies Research Center.

On a personal note, I thank the members of the IOM Committee on the Assessment of Agent-Based Models to Inform Tobacco Product Regulation, who volunteered their time from their very busy professional lives to participate on the committee. I deeply appreciated their dedication and commitment to help guide FDA and the nation on this critical topic.

Robert Wallace, Chair
Committee on the Assessment of Agent-Based Models to Inform Tobacco Product Regulation

Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R1
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R2
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R3
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R4
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R5
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R6
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R7
Page viii Cite
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R8
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R9
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R10
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R11
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R12
Page xiii Cite
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R13
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R14
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R15
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R16
Page xvii Cite
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R17
Page xviii Cite
Suggested Citation:"Front Matter." Institute of Medicine. 2015. Assessing the Use of Agent-Based Models for Tobacco Regulation. Washington, DC: The National Academies Press. doi: 10.17226/19018.
×
Page R18
Next: Summary »
Assessing the Use of Agent-Based Models for Tobacco Regulation Get This Book
×
 Assessing the Use of Agent-Based Models for Tobacco Regulation
Buy Paperback | $55.00 Buy Ebook | $44.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Tobacco consumption continues to be the leading cause of preventable disease and death in the United States. The Food and Drug Administration (FDA) regulates the manufacture, distribution, and marketing of tobacco products - specifically cigarettes, cigarette tobacco, roll-your-own tobacco, and smokeless tobacco - to protect public health and reduce tobacco use in the United States. Given the strong social component inherent to tobacco use onset, cessation, and relapse, and given the heterogeneity of those social interactions, agent-based models have the potential to be an essential tool in assessing the effects of policies to control tobacco.

Assessing the Use of Agent-Based Models for Tobacco Regulation describes the complex tobacco environment; discusses the usefulness of agent-based models to inform tobacco policy and regulation; presents an evaluation framework for policy-relevant agent-based models; examines the role and type of data needed to develop agent-based models for tobacco regulation; provides an assessment of the agent-based model developed for FDA; and offers strategies for using agent-based models to inform decision making in the future.

READ FREE ONLINE

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!