APA (7th ed.) Citation

Lawhead, S. R., Posen, M., & Peterson, E. (1990). Taliesin. Avon Books.

Chicago Style (17th ed.) Citation

Lawhead, Stephen R., Mike Posen, and Eric Peterson. Taliesin. New York: Avon Books, 1990.

MLA (9th ed.) Citation

Lawhead, Stephen R., et al. Taliesin. Avon Books, 1990.