Revised and updated, this compendium helps readers identify and understand the scope of key government reference sources-traditional books (including publications catalogs and telephone directories); information clearinghouses; and materials in new formats, such as CD-ROMs, datafiles, and Internet sites. The authors focus on free information and depository materials-both readily available through toll-free phone numbers, mail or e-mail requests to agencies, or federal depository library collections. Materials are fully described in annotations that differentiate between similar materials, identify typical citation formats, and note common abbreviations