Lua APA (7ú heag.)

Villegas, B. M. (2001). The crisis of childless societies. Manila Bulletin.

Lua i Stíl Chicago (17ú heag.)

Villegas, Bernardo M. "The Crisis of Childless Societies." Manila Bulletin 2001.

Lua MLA (9ú heag.)

Villegas, Bernardo M. "The Crisis of Childless Societies." Manila Bulletin, 2001.

Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.