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.
ציטוט MLANational Fertilizer Development Center. Fertilizer Trends. Washington, D.C: National Fertilizer Development Center, 1973.
אזהרה: ציטוטים אלה לעיתים לא מדויקים ב 100%.