APA استشهاد

DOUGLAS, M., & NORMAN, D. (2007). FARMING SYSTEMS DEVELOPMENT AND SOIL CONSERVATION.

استشهاد بنمط شيكاغو

DOUGLAS, MALCOLM, و DAVID NORMAN. FARMING SYSTEMS DEVELOPMENT AND SOIL CONSERVATION. DELHI, DAYA PUBLISHING HOUSE, 2007.

MLA استشهاد

DOUGLAS, MALCOLM, و DAVID NORMAN. FARMING SYSTEMS DEVELOPMENT AND SOIL CONSERVATION. 2007.