Hopkins, C. G. (1910). Soil fertility and permanent agriculture. Ginn.
Chicagoスタイル(17版)引用形式Hopkins, Cyril G. Soil Fertility and Permanent Agriculture. Boston, New York: Ginn, 1910.
MLA(8版)引用形式Hopkins, Cyril G. Soil Fertility and Permanent Agriculture. Ginn, 1910.
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