Unlocking FBI Files: Guide to Records & Classification System | Research, History & Investigations" （如果原始标题是中文，翻译优化后为：） "FBI档案解密指南：记录与分类系统详解 | 历史研究、调查取证必备

This volume is the first comprehensive guide to the records of the FBI. At last historians have clear descriptions of the FBI's documents and how to gain access to them. Dr. Gerald Haines, who was a member of the National Archives FBI Task Force, and Mr. David Langbart describe the contents of each of the 278 classifications the bureau uses to organize its records. They detail how much material exists, its history, where it is housed, plans for its ultimate disposition, and how one can gain access. The volume includes descriptions of unclassified records; lists of abbreviations used on FBI documents; a full explanation of the FOIA with a sample letter requesting access; organizational charts; and other useful information. This book's combination of practical advice and archival surveys will enable researchers to exploit fully this largely untapped collection of U.S. government records.