APA استشهاد

R. Hay, D. (1988). Planning now for Irrigation and Drainage in the 21st century. American society of Civil Engineers.

استشهاد بنمط شيكاغو

R. Hay, Delynn. Planning Now for Irrigation and Drainage in the 21st Century. New York: American society of Civil Engineers, 1988.

MLA استشهاد

R. Hay, Delynn. Planning Now for Irrigation and Drainage in the 21st Century. American society of Civil Engineers, 1988.