Levi, Werner
Westview Press, 1991
Buku Teks
Starr, John Bryan, author
Harper & Row, 1973
Buku Teks
Columbia University Press, 1946
Buku Teks
Barnes, Harry Elmer, author
Prentice-Hall, 1950
Buku Teks
John Baylis, editor, James J. Wirtz, editor ,Colin S. Gray, editor
Oxford University Press, 2013
Buku Teks