APA (7th ed.) Citation

Oliver, C., & Sobel, R. (1973). People and regions of the world. Laidlaw Brothers.

Chicago Style (17th ed.) Citation

Oliver, Carl, and Robert Sobel. People and Regions of the World. River Forest, Ill.: Laidlaw Brothers, 1973.

MLA (9th ed.) Citation

Oliver, Carl, and Robert Sobel. People and Regions of the World. Laidlaw Brothers, 1973.