Benjamin B. Wolman, editor; George Stricker, co-editor
John Wiley & Sons, 1994
Buku Referensi
Corbetta, Piergiorgio
Sage Publications , 2003
Buku Teks
Lodico, Marguerite G.
Jossey-Bass, 2010
Buku Teks
edited by Kathryn Dean
Sage, 1993
Buku Teks
Galtung, Johan
George Allen and Unwin, 1969
Buku Teks