Gaya APA
Group processes. (1989).
London:
Sage Publications.
Gaya Chicago
Group processes.
text.
London:
Sage Publications,
1989.
.
Gaya MLA
Group processes.
text.
London:
Sage Publications,
1989.
.
Gaya Turabian
Group processes.
London:
Sage Publications,
1989.
.