National Fertilizer Development Center. (1973). Fertilizer trends. Washington, D.C: National Fertilizer Development Center.
Trích dẫn kiểu ChicagoNational Fertilizer Development Center. Fertilizer Trends. Washington, D.C: National Fertilizer Development Center, 1973.
Deismireacht MLANational Fertilizer Development Center. Fertilizer Trends. Washington, D.C: National Fertilizer Development Center, 1973.
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