Singer, J. David
Westview Press , 1990
Buku Teks
Lamont, Christopher K., author
Sage Publications Ltd., 2015
Buku Teks
Gilpin, Robert, author
Cambridge University Press, 1981
Buku Teks
Jackson, Patrick Thaddeus, 1972-, author
Routledge, 2016
Buku Teks
Deutsch, Karl W
Prentice-Hall, 1978
Buku Teks