Philippines. National Mapping & Resource Information Authority. Laoag. National Mapping & Resource Information Authority, 1990.
Cita Chicago (17th ed.)Philippines. National Mapping & Resource Information Authority. Laoag. Makati, Metro Manila: National Mapping & Resource Information Authority, 1990.
Cita MLA (9th ed.)Philippines. National Mapping & Resource Information Authority. Laoag. National Mapping & Resource Information Authority, 1990.
Atenció: Aquestes cites poden no estar 100% correctes.