APA (7th ed.) Citation

Hornby, G. (1980). Your national parks: A state-by-state guide. Crown Publishers.

Chicago Style (17th ed.) Citation

Hornby, George. Your National Parks: A State-by-state Guide. New York: Crown Publishers, 1980.

MLA (9th ed.) Citation

Hornby, George. Your National Parks: A State-by-state Guide. Crown Publishers, 1980.