Kirk J. Schneider, J. Fraser Pierson, James F.T. Bugental, editor
Sage Publications, 2001
Buku Teks
editor, Kirk J. Schneider, James F.T. Bugental, J. Fraser Pierson
Sage Publications, 2001
Buku Referensi
Cohen, John
George Allen & Unwin, 1958
Buku Teks
Tageson, C. William
Dorsey Press, 1982
Buku Teks
[edited by] Elaine Lynne La Monica
Wadsworth Health Sciences Division, 1985
Buku Teks SO