Calkins, E. (1979). Adventure at beaver falls. Southern Publishing Association.
Lua i Stíl Chicago (17ú heag.)Calkins, Erling. Adventure at Beaver Falls. Nashville, TN: Southern Publishing Association, 1979.
Lua MLA (9ú heag.)Calkins, Erling. Adventure at Beaver Falls. Southern Publishing Association, 1979.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.