(1972). Population and heirarchy of cities and municipalities: Bicol region. [s.n.].
Lua i Stíl Chicago (17ú heag.)Population and Heirarchy of Cities and Municipalities: Bicol Region. [Manila]: [s.n.], 1972.
Lua MLA (9ú heag.)Population and Heirarchy of Cities and Municipalities: Bicol Region. [s.n.], 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.