Valera, A. (1980). Field studies on water use and duration for land preparation for lowland rice [microform]. Photoduplication Service. University of the Philippines Library.
Dyfyniad Arddull ChicagoValera, Alfredo. Field Studies on Water Use and Duration for Land Preparation for Lowland Rice [microform]. Quezon City: Photoduplication Service. University of the Philippines Library, 1980.
Dyfyniad MLAValera, Alfredo. Field Studies on Water Use and Duration for Land Preparation for Lowland Rice [microform]. Photoduplication Service. University of the Philippines Library, 1980.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.