APA (7th ed.) Citation

Harris, T. A. (1973). I'm OK -- you're OK. Pan Books Ltd., Avon Books..

Chicago Style (17th ed.) Citation

Harris, Thomas Anthony. I'm OK -- You're OK. London : New York: Pan Books Ltd., Avon Books., 1973.

MLA (8th ed.) Citation

Harris, Thomas Anthony. I'm OK -- You're OK. Pan Books Ltd., Avon Books., 1973.