Johnson, D. W. (1982). Joining together: Group theory and group skills. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Johnson, David W. Joining Together: Group Theory and Group Skills. Prentice-Hall, 1982.
Lua MLA (8ú heag.)Johnson, David W. Joining Together: Group Theory and Group Skills. Prentice-Hall, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.