Cita APA (7th ed.)

Philippines. National Mapping and Resource Information Authority. (1990). Region I (Ed.1, November, 1989.). National Mapping and Resource Information Authority.

Cita Chicago (17th ed.)

Philippines. National Mapping and Resource Information Authority. Region I. Ed.1, November, 1989. Makati City: National Mapping and Resource Information Authority, 1990.

Cita MLA (9th ed.)

Philippines. National Mapping and Resource Information Authority. Region I. Ed.1, November, 1989. National Mapping and Resource Information Authority, 1990.