| Type | Report |
| Title | Classifying physical environments as a tool in cropping systems research: 1 upland rice in the Philippines |
| Author(s) | |
| Publication (Day/Month/Year) | 1976 |
| URL | http://pdf.usaid.gov/pdf_docs/PNAAT784.pdf |
| » | Philippines - Census 1960 |
| » | Philippines - Census of Population and Housing 1970 |