Nicklaus, Jack, author
Harry N. Abrams, 2002
Buku Teks
editor, Cat Sharpe
[American Society for Training & Development;, ], 2005
eBooks
Dubin, Fraida, author
Cambridge University Press, 1986
Buku Teks
Edwards, Clive, author
Page One, 2009
Buku Referensi
Itten, Johannes, author
John Wiley & Sons, 1975
Buku Teks