Geldard, Kathyrn, author
Sage, 2002
Buku Teks
Thomson, Anne, author
Routledge , 1996
Buku Teks
Harvey, Lee, author
Macmillan, 1993
Buku Teks
edited by M. Whitfield, D. Jagner
John Wiley & Sons, 1981
Buku Teks
Kinicki, Angelo, author
McGraw-Hill, 2008
Buku Teks