The new edition of "Library and Reference Facilities in the Area of the District of Columbia" contains information on 426 libraries. It describes information facilities that offer service to the public. Some libraries serving only a restricted clientele are also identified and described because they possess unique or specialized collections. A statement concerning regulations for such library collections indicates the conditions under which permission may be obtained for their use. A subject index, an index of librarians and a listing of disestablished libraries are included at the end of this directory. Changes in names of libraries are provided for by cross-references. The revised edition represents the first publication of The Joint Venture, a nonprofit cooperative endeavor of the American Society for Information Science, the Biological Sciences Communication Project of The George Washington University, the District of Columbia Library Association, the D.C. Chapter of Special Libraries Association and the Federal Library Committee. The group was formed in January 1971 to meet the needs of the library-information science community for useful reference tools which would not ordinarily be published. (Author/AB)