For MLA style, use a parenthetic reference within the body of the essay which would refer back to the government source in the Works Cited page. Use author's last name and page number.
See this example: "Samson argued this point in the President's meeting," (Hansen 145)
Note that government source citations follow the same guidelines, with few exceptions. Use abbreviations for certain organizations, including "Cong." (short for Congress) and "Dept" (short for Department). Treat the government organization as the author if no author is listed. Also, most government sources are printed by the Government Printing Office (GPO), which should also be listed in the Works Cited page.
These examples are furbished by the University of Nebraska Kearney:
United States. Cong. A Descriptive Catalogue of the Government Publications of the United States, September 5, 1774-March 4, 1881. Comp. Benjamin Perley Poore. 48th Cong., 2nd sess. Misc. Doc. 67, Washington: GPO, 1885. Print.
United States. Dept. of Labor. Employment and Training Administration. Dictionary of Occupational Titles. 4th ed. Washington: GPO, 1977. Print.
Use the "author-date" method of citation for APA, which also prefers a citation of sources within the text over footnotes. Example: "Ferguson went against the rules of the council," (Johnson 2008).
This example of an APA citation is from the University of Nebraska Kearney:
Federal Aviation Administration. (2004). Seaplane, ski plane, and float/ski equipped helicopter operations handbook (FAA-H-8083-23). Washington, DC: Government Printing Office.
Note that the Government Printing Office is not abbreviated in the APA citation, but completely written out.
Note that the Chicago Manual style of citation prefers the use of footnotes to tie with the bibliography, as opposed to in-text citations. Within the essay, place a footnote after the sentence with a number that corresponds to the cited source in the bibliography. Note that with cited sources, organization and department names are not abbreviated. The citation methods are otherwise similar to APA and MLA styles. Make sure to check the most recent Chicago Manual of Style handbook for any unusual cases or changes between editions.