APA Citation Style does not have a separate category for government publications. According to APA, government documents can be considered Books, Technical/Research Reports or Brochures.
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Poore, Benjamin Perley. A Descriptive Catalogue of the Government Publications of the United States, Sept. 5, 1774-March 4, 1881. Location
Superintendent of Documents. Checklist of United States Public Documents, 1789-1909. Location
Lester, Daniel W. et al, compilers. Cumulative Title Index to United State Public Documents, 1798-1976. Location
Buchanan, William W. and Edna A. Kanely. Cumulative Subject Index to the Monthly Catalog of United States Government Publications, 1900-1971. Location
Ames, John G. Comprehensive Index to the Publications of the United States Government, 1881-1893. Location
Hickcox, John H. Cumulative Index to Hickcox's Monthly Catalog with Superintendent of Documents Classification (SuDoc) numbers added by Mary Elizabeth Poole. Location
Superintendent of Documents. Catalog of the Public Documents of Congress and of Other Departments of the Government of the United States for the Period of March 4, 1893-December 31, 1940. (known as the Document Catalog) Location
Przebienda, Edward, ed. United States government publications monthly catalog; cumulative personal author index. 1941-1975. Decennial & Quinquennial Cumulative Personal Author Index. Location
Superintendent of Documents. Monthly Catalog of United States Government Publications (title varies slightly between 1895-2000). Continued by: Catalog of Government Publications. Location: Government Document Stacks, Call No: GP 3.8
Guide to U.S. Government Publications. (also known as Andriot after the original editor) Location