Abel, W. (1980). Agricultural fluctuations in Europe from the thirteenth to the twentieth centuries. St. Martin's Press.
Tohutoru Kātū Chicago (17th ed.)Abel, Wilhelm. Agricultural Fluctuations in Europe from the Thirteenth to the Twentieth Centuries. New York: St. Martin's Press, 1980.
Tohutoro MLA (9th ed.)Abel, Wilhelm. Agricultural Fluctuations in Europe from the Thirteenth to the Twentieth Centuries. St. Martin's Press, 1980.