Gaya APA

Johnson, D, W., Johnson, F, P. (1982). Joining together group theory and group skills (2nd ed). Englewood Cliffs, NJ: Prentice Hall.

Gaya MLA

Johnson, David, W.., Johnson, Frank, P.. "Joining together group theory and group skills". 2nd ed Englewood Cliffs, NJ: Prentice Hall, 1982. Text.