APA (7th ed.) Citation

Tomkins, G. S., Hills, T. L., & Weir, T. R. (1970). A regional geography of North America (2d ed.). Gage Educational Publishing Ltd..

Chicago Style (17th ed.) Citation

Tomkins, George S., Theo L. Hills, and Thomas R. Weir. A Regional Geography of North America. 2d ed. Toronto: Gage Educational Publishing Ltd., 1970.

MLA (9th ed.) Citation

Tomkins, George S., et al. A Regional Geography of North America. 2d ed. Gage Educational Publishing Ltd., 1970.