Dyfyniad APA

Keffer, C. A. (1907). Nature studies on the farm: Soils and plants. American Book Co..

Dyfyniad Arddull Chicago

Keffer, Charles A. Nature Studies on the Farm: Soils and Plants. New York: American Book Co., 1907.

Dyfyniad MLA

Keffer, Charles A. Nature Studies on the Farm: Soils and Plants. American Book Co., 1907.

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