Gomm, Roger, author
Palgrave McMillan, 2004
Buku Teks
Zechmeister, Eugene B., author
McGraw-Hill, 1992
Buku Teks
McInerney, Dennis M., author
Sage Publication, 2001
Buku Teks
Barker, Chris, author
John Wiley & Sons, 2002
Buku Teks
Bell, Phillip, author
Sage, 2001
Buku Teks