Não informado. (1935). Iowa farm economist. Iowa State College of Agriculture and Mechanic Arts.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Iowa Farm Economist. Ames, Iowa: Iowa State College of Agriculture and Mechanic Arts, 1935.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Iowa Farm Economist. Iowa State College of Agriculture and Mechanic Arts, 1935.
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