De Guzman, S. A. (1997). Preserving the ancient rock art of Angono. Philippine Daily Inquirer.
Lua i Stíl Chicago (17ú heag.)De Guzman, Susan A. "Preserving the Ancient Rock Art of Angono." Philippine Daily Inquirer 1997.
Lua MLA (9ú heag.)De Guzman, Susan A. "Preserving the Ancient Rock Art of Angono." Philippine Daily Inquirer, 1997.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.