Citazione Stile APA (7a Edizione)

(1972). Population and heirarchy of cities and municipalities: Bicol region. [s.n.].

Citazione stile Chigago Style (17a edizione)

Population and Heirarchy of Cities and Municipalities: Bicol Region. [Manila]: [s.n.], 1972.

Citatione MLA (9a ed.)

Population and Heirarchy of Cities and Municipalities: Bicol Region. [s.n.], 1972.