1. Barell, G. (1971). Group Sex. Wyden, New York.
2. Breedlove, W., Breedlove, J. (1971). Swap Clubs. Sherbourne, Los Angeles.
3. Combs, A., Snygg, D. (1959). Individual Behavior: A Perceptual Approach. Harpers, New York.
4. Constantine, L., Constantine, J. (1973). Group Marriage. Macmillan, New York