631.8
C50C
           Collings, Gilbeart H
               Commercial fertilizers their sources and use \ Gilbeart H Collings - 4th - Philadelphia : Blakiston, 1947.
               xi, 522p:ill+tab - Blakiston books on agriculture/ed. by Gilbeart H Collings .
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                Subjects: Fertilizers; Fertilizer industry; Agricultural chemicals industry; Ammonia as fertilizer; Potassium fertilizer.