World Resources Institute, United Nations Environment Programme, & United Nations Development Programme. (1990). World resources. Oxford University Press.
Lua i Stíl Chicago (17ú heag.)World Resources Institute, United Nations Environment Programme, agus United Nations Development Programme. World Resources. New York: Oxford University Press, 1990.
Lua MLA (8ú heag.)World Resources Institute, et al. World Resources. Oxford University Press, 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.