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All Books by author - Cyril G. (Cyril George) Hopkins

The Story of the Soil; from the Basis of Absolute Science and Real Life

Nitrogen Bacteria and Legumes With special reference to red clover, cowpeas, soy beans, alfalfa, and sweet clover, on Illinois soils

Nitrifying bacteria

Nitrogen-fixing microorganisms

The Farm That Won't Wear Out

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