The 1920 federal population census :
a catalog of National Archives microfilm.
APA Citation
United States. National Archives and Records Administration. (1991). The 1920 federal population census: a catalog of National Archives microfilm. Washington, D.C.: National Archives and Records Administration.
MLA Citation
United States. National Archives and Records Administration. The 1920 Federal Population Census: a Catalog of National Archives Microfilm. Washington, D.C.: National Archives and Records Administration, 1991.
Warning: These citations may not always be complete (especially for serials).