Cita APA

Middleton, N., Weston, S., & Downes, J. (1989). Atlas of environmental issues. Facts on File.

Citación estilo Chicago

Middleton, Nick, Steve Weston, and John Downes. Atlas of Environmental Issues. New York: Facts on File, 1989.

Cita MLA

Middleton, Nick, et al. Atlas of Environmental Issues. Facts on File, 1989.