Lee, Stuart D.
Facet Publishing, 2004
Buku Teks SO
Kohn, Karen C., 1978
Rowman & Littlefield, 2015
Buku Teks SO
Richard, Lyn, Author
Sage, 2014
Buku Teks SO
Durell, William
McGraw-Hill, 1985
Buku Teks SO
edited by Harry R. Karp
McGraw-Hill, 1980
Buku Referensi