The American Psychological Association,
Majalah, Jurnal, Buletin
Taylor, Shelley E.
McGraw-Hill, 2012
Buku Teks SO
DiMatteo, M. Robin
Allyn and Bacon, 2002
Buku Teks
editor, David F. Marks
Sage Publications, 2002
Buku Teks SO
edited by Henry Wechsler, Leonard Solomon, Bernard M. Kramer
Holt, Rinehart and Winston, 1970
Buku Teks SO