APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

Tomkins, George S., and Theo L. Hills. A Regional Geography of North America. 2d ed. Toronto: Gage Educational Pub, 1970.

MLA (9th ed.) Citation

Tomkins, George S., and Theo L. Hills. A Regional Geography of North America. 2d ed. Gage Educational Pub, 1970.