War Diary of His Majesty's Submarine U-20

Chicago citation style
Department of the Navy. Office of the Chief of Naval Operations. Office of the Deputy Chief of Naval Operations (Operations). Naval Intelligence Division. Office of Naval Records and Library. (8/1/1946 - 9/18/1947). War Diary of His Majesty's Submarine U-20. 1915. Retrieved from the Digital Public Library of America, http://catalog.archives.gov/id/785591. (Accessed June 18, 2018.)
APA citation style
Department of the Navy. Office of the Chief of Naval Operations. Office of the Deputy Chief of Naval Operations (Operations). Naval Intelligence Division. Office of Naval Records and Library. (8/1/1946 - 9/18/1947), (1915) War Diary of His Majesty's Submarine U-20. Retrieved from the Digital Public Library of America, http://catalog.archives.gov/id/785591
MLA citation style
Department of the Navy. Office of the Chief of Naval Operations. Office of the Deputy Chief of Naval Operations (Operations). Naval Intelligence Division. Office of Naval Records and Library. (8/1/1946 - 9/18/1947). Retrieved from the Digital Public Library of America <http://catalog.archives.gov/id/785591>.
Note: These citations are programmatically generated and may be incomplete.