Philippines. National Mapping and Resource Information Authority. (1990). Region I (Ed.1, November, 1989.). National Mapping and Resource Information Authority.
Citazione stile Chigago Style (17a edizione)Philippines. National Mapping and Resource Information Authority. Region I. Ed.1, November, 1989. Makati City: National Mapping and Resource Information Authority, 1990.
Citatione MLA (9a ed.)Philippines. National Mapping and Resource Information Authority. Region I. Ed.1, November, 1989. National Mapping and Resource Information Authority, 1990.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.