WHO. 2005. Clarification: Use of Masks by Healthcare Workers in Pandemic Settings. Geneva: WHO.
WHO. 2006. Avian Influenza, Including Influenza A (H5N1), in Humans: WHO Interim Infections Control Guidelines for Health Care Facilities. Geneva: WHO.
WHO Writing Group. 2006. Nonpharmaceutical interventions for pandemic influenza, national and community measures. Emerging Infectious Diseases 12(1):88–94.
Wu J, Xu F, Zhou W, Feikin DR, Lin CY, He X, Zhu Z , Liang W, Chin DP, Schuchat A. 2004. Risk factors for SARS among persons without known contact with SARS patients, Beijing, China. Emerging Infectious Diseases 10(2):210–216.