McGovern, G. S. (1967). Agricultural thought in the twentieth century. Bobbs-Merill.
Chicago Style (17. basım) AtıfMcGovern, George Stanley. Agricultural Thought in the Twentieth Century. Indianapolis: Bobbs-Merill, 1967.
MLA (9th ed.) AtıfMcGovern, George Stanley. Agricultural Thought in the Twentieth Century. Bobbs-Merill, 1967.
Uyarı: Bu alıntı herzaman %100 doğru olmayabilir..