Umali, R. M. (1976). Outline of taxation. Rex Book Store.
Lua i Stíl Chicago (17ú heag.)Umali, Roman M. Outline of Taxation. Manila: Rex Book Store, 1976.
Lua MLA (9ú heag.)Umali, Roman M. Outline of Taxation. Rex Book Store, 1976.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.