Artikel Jurnal
Mohammad Adi Ganjar Priadi
Fakultas Psikologi Universitas Indonesia, 2013
UI - Tesis Membership
Nugent, Frank A., 1921-
Charles E. Merrill, 1990
Buku Teks SO
Hackney, Harold
Allyn and Bacon, 2000
Buku Teks SO
Nelson-Jones, Richard
Sage Publications, 2004
Buku Teks