Philippines. National Mapping & Resource Information Authority. Calayan Island. National mapping and Resource Information Authority, 1989.
Cita Chicago (17th ed.)Philippines. National Mapping & Resource Information Authority. Calayan Island. Makati, Metro Manila: National mapping and Resource Information Authority, 1989.
Cita MLA (9th ed.)Philippines. National Mapping & Resource Information Authority. Calayan Island. National mapping and Resource Information Authority, 1989.
Atenció: Aquestes cites poden no estar 100% correctes.