Edensor, Tim, author
Berg Publishers, 2002
Buku Teks
edited by Marcello Truzzi
Prentice-Hall, 1968
Buku Teks
Ople, Blas F., author
The Institute for Public Policy, 2001
Buku Teks
Heilbroner, Robert L., author
Norton, 1974
Buku Teks
Inglis, David, author
Routledge, 2005
Buku Teks