Não informado. (1937). Plant inventory. Bureau of Plant Industry, Soils and Agricultural Engineering.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Plant Inventory. Washington: Bureau of Plant Industry, Soils and Agricultural Engineering, 1937.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Plant Inventory. Bureau of Plant Industry, Soils and Agricultural Engineering, 1937.
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