Nebel, B. J. (1998). Environmental sciencethe way the world works. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Nebel, Bernard J. Environmental Sciencethe Way the World Works. Prentice-Hall, 1998.
Lua MLA (8ú heag.)Nebel, Bernard J. Environmental Sciencethe Way the World Works. Prentice-Hall, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.