1940 Census Enumeration District Maps - Pennsylvania - Beaver County - Beaver - ED 4-37, ED 4-38, ED 4-39, ED 4-40, ED 4-41

Chicago citation style
Department of Commerce. Bureau of the Census. Office of the Associate Director for Decennial Census. Geography Division. (1/1987 - 7/15/2011). 1940 Census Enumeration District Maps - Pennsylvania - Beaver County - Beaver - ED 4-37, ED 4-38, ED 4-39, ED 4-40, ED 4-41. 1880-01-01/1990-12-31. Retrieved from the Digital Public Library of America, http://catalog.archives.gov/id/5836763. (Accessed June 20, 2018.)
APA citation style
Department of Commerce. Bureau of the Census. Office of the Associate Director for Decennial Census. Geography Division. (1/1987 - 7/15/2011), (1880-01-01/1990-12-31) 1940 Census Enumeration District Maps - Pennsylvania - Beaver County - Beaver - ED 4-37, ED 4-38, ED 4-39, ED 4-40, ED 4-41. Retrieved from the Digital Public Library of America, http://catalog.archives.gov/id/5836763
MLA citation style
Department of Commerce. Bureau of the Census. Office of the Associate Director for Decennial Census. Geography Division. (1/1987 - 7/15/2011). Retrieved from the Digital Public Library of America <http://catalog.archives.gov/id/5836763>.
Note: These citations are programmatically generated and may be incomplete.