Não informado. (1945). Down to earth: A review of agricultural chemical progress. Down Chemical, Agricultural Products Department.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Down to Earth: A Review of Agricultural Chemical Progress. Midland, Mich: Down Chemical, Agricultural Products Department, 1945.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Down to Earth: A Review of Agricultural Chemical Progress. Down Chemical, Agricultural Products Department, 1945.
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