Gatdula, L. S. (1999). Roy Alvarez says healing the environment starts with M.E. Philippine Daily Inquirer.
Lua i Stíl Chicago (17ú heag.)Gatdula, Leah Salterio. "Roy Alvarez Says Healing the Environment Starts with M.E." Philippine Daily Inquirer 1999.
Lua MLA (9ú heag.)Gatdula, Leah Salterio. "Roy Alvarez Says Healing the Environment Starts with M.E." Philippine Daily Inquirer, 1999.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.