edited by John Baylis and Steve Smith
Oxford University Press, 2006
Buku Teks
Friedmann, Wolfgang, 1907-1972, author
Vorkonk-Van Hoeve, 1976
Buku Teks
Ethridge, Marcus E., author
Wadsworth and Cengage Learning, 2013
Buku Teks
John Baylis, Steve Smith, Patricia Owens.
Oxford University Press, 2014
Buku Teks
Organski, A.F.K., author
Alfred A. Knopf, 1969
Buku Teks