Παραπομπή APA

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

Παραπομπή Chicago Style

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

Παραπομπή MLA

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