keep their eyes open for new or other publications for their own lists of references. The absence of any volume or periodical from these lists is not intended as a comment on its quality or usefulness.

Insofar as possible, the most current edition of a publication is annotated in part 3. However, later editions of some volumes, particularly annual or biannual directories, may have appeared after the text of Resources for Teaching Middle School Science was completed.

Prices for the books and periodicals in chapters 7 through 9 are given in the annotations. Costs for shipping and handling are not included. The addresses, telephone and fax numbers, and e-mail addresses, when available, for publishers of these materials are in appendix A, "Publishers and Suppliers."

Every effort was made to provide accurate, up-to-date ordering information. However, because of frequent changes in company names, addresses, and telephone and fax numbers, readers may wish to consult annually updated directories, such as NSTA Science Education Suppliers (see 8.22), or standard reference directories such as Books in Print from their local libraries or bookstores.

Likewise, because prices and availability may change, readers should check the prices of publications or supplies listed before placing an order. They are encouraged to contact publishers directly for current ordering information (including shipping charges). In some cases, discounts or special rates may be available to schools and educators.