Gaya APA

dkk, A, I. (1992). Conservation Policies For Sustainable Hilslope Farming (Cetakan Pertama). USA: Soil and Water Conservation Society.

Gaya MLA

dkk, Arsyad, Istanala.,. "Conservation Policies For Sustainable Hilslope Farming". Cetakan Pertama USA: Soil and Water Conservation Society, 1992. Text.