Cohen, S. B. (1967). Geography and the American environment. s.n.
Lua i Stíl Chicago (17ú heag.)Cohen, Saul B. Geography and the American Environment. Washington, D.C: s.n, 1967.
Lua MLA (9ú heag.)Cohen, Saul B. Geography and the American Environment. s.n, 1967.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.