Chiras, D. D. (1998). Environmental science: A systems approach to sustainable development (5th ed.). Wadsworth Publishing Company.
Lua i Stíl Chicago (17ú heag.)Chiras, Daniel D. Environmental Science: A Systems Approach to Sustainable Development. 5th ed. Belmont: Wadsworth Publishing Company, 1998.
Lua MLA (9ú heag.)Chiras, Daniel D. Environmental Science: A Systems Approach to Sustainable Development. 5th ed. Wadsworth Publishing Company, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.