APA
Walker W. R., Food and Agriculture Organization of the United Nations, . (1989). Guidelines for designing and evaluating surface irrigation systems. Rome: FAO.
Chicago
Walker W R, Food and Agriculture Organization of the United Nations, . 1989. Guidelines for designing and evaluating surface irrigation systems. Rome: FAO.
Harvard
Walker W. R., Food and Agriculture Organization of the United Nations, . (1989). Guidelines for designing and evaluating surface irrigation systems. Rome: FAO.
MLA
Walker W R, Food and Agriculture Organization of the United Nations, . Guidelines for designing and evaluating surface irrigation systems. Rome: FAO. 1989.