Viotti, Paul R
Longman, 2012
Buku Teks
Holsti, Kalevi J., author
Prentice-Hall, 1992
Buku Teks
Reynolds, P.A., author
Longman, 1994
Buku Teks
edited by Klaus Knorr and James N. Rosenau
Priceton University Press, 1969
Buku Teks
edited by William T.R. Fox
Indiana University of Notre Dame Press , 1959
Buku Teks