Napier, R. W. (1981). Groups: Theory and experience (2nd.ed.). Houghton Mifflin.
Cita Chicago (17th ed.)Napier, Rodney W. Groups: Theory and Experience. 2nd.ed. Boston: Houghton Mifflin, 1981.
Cita MLA (9th ed.)Napier, Rodney W. Groups: Theory and Experience. 2nd.ed. Houghton Mifflin, 1981.
Atenció: Aquestes cites poden no estar 100% correctes.