Readers often consider government publications more credible than others, so they make good sources for research. According to the sixth edition of the "Publication Manual of the American Psychological Association," sources such as the U.S. Census require particular documentation format both in the parenthetical citations and the references page.
Parenthetical references for census data use the name of the organization and the publication year for the specific reference with a comma in between: (U.S. Census Bureau, 2012). The References page entry begins with the bureau and a period. The date appears in parentheses next, with a period after. Give the title of the document or Web page, italicized, capitalizing only the first word and proper nouns. Include "Report No." (without the quotation marks) and the number in parentheses right after the title if your source has one. Print sources then need the publication city, a colon and the publisher. For Internet data, replace publisher details with "Retrieved from" (without the quotation marks) and the entire URL. For example:
U.S. Census Bureau. (2012). Electronic ownership by household (italicized). Washington, D.C.: Government Printing Office. U.S. Census Bureau. (2012). Electronic ownership by household (italicized). Retrieved from http://www.census.gov/data/2012