APA (7th ed.) Citation

Ryan, W. T. (1981). A guide to marketing. Richard D. Irwin, Inc.

Chicago Style (17th ed.) Citation

Ryan, Willliam T. A Guide to Marketing. Illinois: Richard D. Irwin, Inc, 1981.

MLA (8th ed.) Citation

Ryan, Willliam T. A Guide to Marketing. Richard D. Irwin, Inc, 1981.