Kort over USA's optællingsdistrikt for det tolvte til det sekstende amerikansk folketællinger, 1900-1940

"United States, Enumeration District Maps for the Twelfth through the Sixteenth US Censuses, 1900-1940." Images. FamilySearch. http://FamilySearch.org : 3 December 2024. Citing NARA microfilm publication A3378. Washington, D.C.: National Archives and Records Administration, 2003.