Kephart, W. M., & William W. Zellner. (1998). Extraordinary groups: An examination of unconventional lifestyles (6th ed.). St. Martin's Press.

Kephart, William M., and William W. Zellner. Extraordinary Groups: An Examination of Unconventional Lifestyles. 6th ed. New York: St. Martin's Press, 1998.

Kephart, William M., and William W. Zellner. Extraordinary Groups: An Examination of Unconventional Lifestyles. 6th ed. St. Martin's Press, 1998.