Robbins, Lionel, author
Macmillan, 1954
Buku Teks
Adler, Karlsson G.
Springer-Verlag, 1976
Buku Teks
edited by Michael Stohl and Harry R. Targ
Schenkman Publishing Company, 1982
Buku Teks
Beck, Ulrich, author
Malden, MA :Polity Press, 2005
Buku Teks
Gill, Stephen, author
John Hopkins University Press, 1988
Buku Teks