United States. Bureau of the Census. (1970). Percent change in corn yield per acre: By counties of the United States : 1939-1964. U.S. Govt. Print. Off..
Chicago Style (17th ed.) CitationUnited States. Bureau of the Census. Percent Change in Corn Yield Per Acre: By Counties of the United States : 1939-1964. Washington: U.S. Govt. Print. Off., 1970.
MLA (8th ed.) CitationUnited States. Bureau of the Census. Percent Change in Corn Yield Per Acre: By Counties of the United States : 1939-1964. U.S. Govt. Print. Off., 1970.
Warning: These citations may not always be 100% accurate.