Hopkins, D. P. (1948). Chemicals, humus, and the soil: A simple presentation of contemporary knowledge and opinions about fertilizers, manures, and soil fertility ([American ed.].). Chemical Pub. Co..
Chicago Style (17th ed.) CitationHopkins, Donald Percy. Chemicals, Humus, and the Soil: A Simple Presentation of Contemporary Knowledge and Opinions About Fertilizers, Manures, and Soil Fertility. [American ed.]. Brooklyn: Chemical Pub. Co., 1948.
MLA (9th ed.) CitationHopkins, Donald Percy. Chemicals, Humus, and the Soil: A Simple Presentation of Contemporary Knowledge and Opinions About Fertilizers, Manures, and Soil Fertility. [American ed.]. Chemical Pub. Co., 1948.
Warning: These citations may not always be 100% accurate.