Kupchella, C. I., & Kupchella, C. I. (1986). Environmental Science: Living Within System Of Nature / Charles E. Kupchella. Allyn and Bacon.
Lua i Stíl Chicago (17ú heag.)Kupchella, Charles I., agus Charles I. Kupchella. Environmental Science: Living Within System Of Nature / Charles E. Kupchella. Allyn and Bacon, 1986.
Lua MLA (8ú heag.)Kupchella, Charles I., agus Charles I. Kupchella. Environmental Science: Living Within System Of Nature / Charles E. Kupchella. Allyn and Bacon, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.