Palmer, Michael, author
Bantam Books, 1993
Buku Teks
Sartain, Libby, author
Amacom , 2003
Buku Teks
Sartain, Libby, author
[American Management Association, ], 2003
eBooks
Sali A. Tagliamonte, author
Cambridge University Press, 2016
Buku Teks
Benny Rhamdani, editor
Cinta, 2006
Buku Teks