APA
Leon J., Withers L., . (1986). Guidelines for seed exchange and plant introduction in tropical crops. Food and Agriculture Organization of the United Nations: Rome.
Chicago
Leon J, Withers L.A, . 1986. Guidelines for seed exchange and plant introduction in tropical crops. Food and Agriculture Organization of the United Nations: Rome.
Harvard
Leon J., Withers L., . (1986). Guidelines for seed exchange and plant introduction in tropical crops. Food and Agriculture Organization of the United Nations: Rome.
MLA
Leon J, Withers L.A, . Guidelines for seed exchange and plant introduction in tropical crops. Food and Agriculture Organization of the United Nations: Rome. 1986.