MLA (Modern Language Association) Example:
7th edition: In general, treat a map or chart like an article or book, but add the appropriate label (Map, Chart). Example of a map in an atlas:
"Allied Occupaton Zones." Map. Atlas of American History. By Robert H. Ferrell
and Richard Natkiel. New York: Facts On File, 1993. 152. Print.
Historical Map Digitized on the Web:
"Boston 1630-1675. The Original Topography and Early Settlement Together with the Present Shore Line." Map.
From the Report on the Social Statistics of Cities. Compiled by George E. Waring, Jr., United States. Census Office, Part I, 1886. Web. 24 May 2008.