Palis, R. G. (1980). Soil erosion under different cover crops [microform]. Photoduplication Service. University of the Philippines Library.
Chicago-referens (17:e uppl.)Palis, Reynaldo Gibas. Soil Erosion Under Different Cover Crops [microform]. Quezon City: Photoduplication Service. University of the Philippines Library, 1980.
MLA-referens (9:e uppl.)Palis, Reynaldo Gibas. Soil Erosion Under Different Cover Crops [microform]. Photoduplication Service. University of the Philippines Library, 1980.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.