Pfeiffer, J. W. (1989). The encyclopedia of group activities: 150 practical dewigns for successful facilitating. Pfeiffer.
Chicago-referens (17:e uppl.)Pfeiffer, J. William. The Encyclopedia of Group Activities: 150 Practical Dewigns for Successful Facilitating. San Diego, Calif: Pfeiffer, 1989.
MLA-referens (9:e uppl.)Pfeiffer, J. William. The Encyclopedia of Group Activities: 150 Practical Dewigns for Successful Facilitating. Pfeiffer, 1989.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.