Cita APA

World Resources Institute, The United Nations Development Programme, & The United Nations Environment Programme. (1992). world resources 1990-91. Oxford: Oxford University Press.

Citación estilo Chicago

World Resources Institute, The United Nations Development Programme, and The United Nations Environment Programme. World Resources 1990-91. Oxford: Oxford University Press, 1992.

Cita MLA

World Resources Institute, The United Nations Development Programme, and The United Nations Environment Programme. World Resources 1990-91. Oxford: Oxford University Press, 1992.