Robson, Brian T., author
Methuen, 1973
Buku Teks
Mann, Peter H., author
Humanities Press, 1965
Buku Teks
Burns, James McGregor, author
Harper and Row, 1978
Buku Teks
Northouse, Peter G., author
Sage, 2010
Buku Teks
edited by Andrew Blowers, Chris Hammett and Philip Sarre
Hutchinson Educational in association with the Open University Press, 1974
Buku Teks