Government  

GPO (U.S. Government Printing Office)

Catalog of U.S. Government Publications

U.S. Government Bookstore

Citing a government document in the APA Style (American Psychological Association):

U.S. Department of Health and Human Services, National Institutes of Health, National
     Heart, Lung, and Blood Institute. (2003). Managing asthama: A guide for schools
     (NIH Publication No. 02-2650).

Citing a government document in the Chicago Style:

Continental Congress. Journals of the Continental Congress, 1774-1789. Edited by
      Worthington C. Ford et. al. 34 vols. Washington, DC, 1904-37.

Citing a government document in the MLA Style (Modern Language Association):

United States. Dept. of Labor. Child Care: A Workforce Issue. Washington: GPO,
       1988. Print.