Pfeiffer, J. W. (1989). The Encyclopedia of group activities: 150 practical designs for successful facilitating. University Associates.
Chicago-referens (17:e uppl.)Pfeiffer, J. William. The Encyclopedia of Group Activities: 150 Practical Designs for Successful Facilitating. San Diego, Calif.: University Associates, 1989.
MLA-referens (8:e uppl.)Pfeiffer, J. William. The Encyclopedia of Group Activities: 150 Practical Designs for Successful Facilitating. University Associates, 1989.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.