Owens, S. E., & Owens, P. L. (1991). Environment, resources, and conservation. Cambridge University Press.
Lua i Stíl Chicago (17ú heag.)Owens, Susan E., agus Peter L. Owens. Environment, Resources, and Conservation. Cambridge: Cambridge University Press, 1991.
Lua MLA (9ú heag.)Owens, Susan E., agus Peter L. Owens. Environment, Resources, and Conservation. Cambridge University Press, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.