Larsen, S. T. (1973). Report of studies on the organization, O and M and equipment of the National Irrigation Administration of the Government of the Philippines [microform]. Photoduplication Service University of the Philippines Library.
Lua i Stíl Chicago (17ú heag.)Larsen, S. T. Report of Studies on the Organization, O and M and Equipment of the National Irrigation Administration of the Government of the Philippines [microform]. Quezon City: Photoduplication Service University of the Philippines Library, 1973.
Lua MLA (9ú heag.)Larsen, S. T. Report of Studies on the Organization, O and M and Equipment of the National Irrigation Administration of the Government of the Philippines [microform]. Photoduplication Service University of the Philippines Library, 1973.