Cita APA (7th ed.)

Tolba, M. K., Lamb, R., & Allen, P. (1983). Earth matters: Environmental challenges for the l980s. United Nations Environment Programme.

Cita Chicago (17th ed.)

Tolba, Mostafa Kamal, Robert Lamb, i Patrick Allen. Earth Matters: Environmental Challenges for the L980s. Nairobi, Kenya: United Nations Environment Programme, 1983.

Cita MLA (9th ed.)

Tolba, Mostafa Kamal, et al. Earth Matters: Environmental Challenges for the L980s. United Nations Environment Programme, 1983.