APA (7th ed.) Citation

Thorpy, M. J., & Yager, J. (2001). The encyclopedia of sleep and sleep disorders / Michael J. Thorpy and Jan Yager (2nd ed., updated and rev.). Facts on File.

Chicago Style (17th ed.) Citation

Thorpy, Michael J., and Jan Yager. The Encyclopedia of Sleep and Sleep Disorders / Michael J. Thorpy and Jan Yager. 2nd ed., updated and rev. New York: Facts on File, 2001.

MLA (9th ed.) Citation

Thorpy, Michael J., and Jan Yager. The Encyclopedia of Sleep and Sleep Disorders / Michael J. Thorpy and Jan Yager. 2nd ed., updated and rev. Facts on File, 2001.

Warning: These citations may not always be 100% accurate.