Dyke, Vernon van
Stanford University Press, 1962
Buku Teks
Apter, David E.
Winthrop, 1977
Buku Teks
Lasswell, Harold D.
Routledge & Kegan Paul Ltd., 1949
Buku Teks
edited by David Ingram
Blackwell , 2002
Buku Teks
Easton, David
John Wiley & Sons, 1965
Buku Teks