APA (7th ed.) Citation

Heynen, W. J. (1976). Agricultural maps in the National Archives of the United States ca.1860-1930. National Archives and Records Service.

Chicago Style (17th ed.) Citation

Heynen, William J. Agricultural Maps in the National Archives of the United States Ca.1860-1930. Washington: National Archives and Records Service, 1976.

MLA (9th ed.) Citation

Heynen, William J. Agricultural Maps in the National Archives of the United States Ca.1860-1930. National Archives and Records Service, 1976.