Culyer, A.J.
Martin Robertson & Company, 1973
Buku Teks
Cronin, James E., author
Routledge, 1991
Buku Teks
Burke, Gill, author
Longman, 1981
Buku Teks
Stein, Theodore J., author
Columbia University Press, 2001
Buku Teks
edited by Peter Dwyer, Sandra M I Shaw
Sage, 2013
Buku Teks