@book{ Solr-1700032, title = {Percent change in the value of farm products sold per acre of land in farms, by counties of the United States : 1939-1964.}, series = {United States maps.}, editor = {United States. Bureau of the Census}, address = {Washington}, publisher = {U.S. Govt. Print. Off.}, year = {1970}, note = {"Albers equal area projection; standard parallels 29 1/2⁰ and 45 1/2⁰."}, note = {Includes tables and inset of Hawaii.}, }