Pfeiffer, J. W. (1989). The Encyclopedia of group activities: 150 practical designs for successful facilitating. University Associates.
Lua i Stíl Chicago (17ú heag.)Pfeiffer, J. William. The Encyclopedia of Group Activities: 150 Practical Designs for Successful Facilitating. San Diego, Calif.: University Associates, 1989.
Lua MLA (8ú heag.)Pfeiffer, J. William. The Encyclopedia of Group Activities: 150 Practical Designs for Successful Facilitating. University Associates, 1989.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.