Dartnell , 1996
Buku Teks
edited by Anita L. Vangelisti, Daniel Perlman
Cambridge University Press, 2006
Buku Referensi
edited by Walter Carlsnaes, Thomas Risse and Beth A. Simmons
Sage, 2013
Buku Teks
edited by Mark R. Gould
[American Management Association, ], 2009
eBooks
Sprague, Jo, author
Wadsworth and Cengage Learning, 2013
Buku Referensi