edited by Andrew Blowers, Chris Hammett and Philip Sarre
Hutchinson Educational in association with the Open University Press, 1974
Buku Teks
Gutkind, E. A.
The Free Press of Glencoe, 1963
Buku Teks
Orum, Anthony M.
Blackwell, 2003
Buku Teks
M.I.T. Press and Harvard University, 1963
Buku Teks
Mercer, Charles
Penguin Books, 1975
Buku Teks