APA (7th ed.) Citation

The princeton language institute, The plilip lief group,inc, & Laskowki, L. (2001). 10 days to more confident public speaking. Warner Books.

Chicago Style (17th ed.) Citation

The princeton language institute, The plilip lief group,inc, and Lenny Laskowki. 10 Days to More Confident Public Speaking. New York: Warner Books, 2001.

MLA (8th ed.) Citation

The princeton language institute, et al. 10 Days to More Confident Public Speaking. Warner Books, 2001.