Independent Petroleum Association of America. The Oil producing industry in your state. Petroleum Independent Publishers.
Lua i Stíl Chicago (17ú heag.)Independent Petroleum Association of America. The Oil Producing Industry in Your State. [Washington: Petroleum Independent Publishers.
Lua MLA (8ú heag.)Independent Petroleum Association of America. The Oil Producing Industry in Your State. Petroleum Independent Publishers.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.