Gitterman, A. a. S. L. (1986). Mutual aid groups and life cicle. F. E. Peacock.
Lua i Stíl Chicago (17ú heag.)Gitterman, Alex and Schulman Lawrence. Mutual Aid Groups and Life Cicle. F. E. Peacock, 1986.
Lua MLA (9ú heag.)Gitterman, Alex and Schulman Lawrence. Mutual Aid Groups and Life Cicle. F. E. Peacock, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.