Cook, E. Man, energy, society. W.H. Freeman and Company.
Lua i Stíl Chicago (17ú heag.)Cook, Earl. Man, Energy, Society. San Francisco: W.H. Freeman and Company.
Lua MLA (9ú heag.)Cook, Earl. Man, Energy, Society. W.H. Freeman and Company.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.