Cambridge University Press, 1995
Buku Teks
Zander, Alvin
Jossey-Bass Publishers, 1994
Buku Teks
Knox, Kim, -1997
Widescope, 1978
Buku Teks
Knox, Frank M.
McGraw-Hill, 1965
Buku Teks
Dawson, Robert MacGregor
The Univ. of Toronto Press , 1959
Buku Teks