Prantilia, Edmundo Barrios, 1940- Economic optimization models of multiple cropping system applied to the Philippines / [microform] : Edmundo Barrios Prantilia - Ann Arbor, Mich. : University Microfilms International, 1972 - 1 microfilm reel : positif ; 35 mm. Thesis (Ph.D.) - Iowa State University, 1972 Subjects--Topical Terms: Multiple--Cropping Systems--Philippine Islands