Sederberg, Peter C.
Chandler & Sharp Publishers, 1977
Buku Teks SO
Scott Frickel; Kelly Moore, editor
University of Wisconsin Press , 2006
Buku Teks SO
edited by David Ingram
Blackwell , 2002
Buku Teks SO
Lasswell, Harold D.
Routledge & Kegan Paul, 1952
Buku Teks SO
Fay, Brian
Pustaka Utama Grafiti, 1991
Buku Teks SO