Cita APA (7a ed.)

(1972). Population density by provinces: Bicol region. [s.n.].

Cita Chicago Style (17a ed.)

Population Density by Provinces: Bicol Region. [Manila]: [s.n.], 1972.

Cita MLA (9a ed.)

Population Density by Provinces: Bicol Region. [s.n.], 1972.