Bernards, N. (1991). The Environmental crisis--opposing viewpoints. Greenhaven Press.
Lua i Stíl Chicago (17ú heag.)Bernards, Neal. The Environmental Crisis--opposing Viewpoints. San Diego, CA: Greenhaven Press, 1991.
Lua MLA (8ú heag.)Bernards, Neal. The Environmental Crisis--opposing Viewpoints. Greenhaven Press, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.