APA引文

(1972). Population map 1970: Cities and municipalities, Bicol region. [s.n.].

Chicago Style (17th ed.) Citation

Population Map 1970: Cities and Municipalities, Bicol Region. [Manila]: [s.n.], 1972.

MLA引文

Population Map 1970: Cities and Municipalities, Bicol Region. [s.n.], 1972.

警告：這些引文格式不一定是100％准確.