Artikel Jurnal
Platteel, Harry
Merweboek, 1967
Buku Teks
Lorrie Lykins, David Wentworth
American Society for Training & Development, 2011
eBooks
Pallasamaa, Juhani, author
John Wiley & Sons Ltd, 2009
Buku Teks
Meir Olivia Halim, author
Fakultas Psikologi Universitas Indonesia, 2004
UI - Tesis (Membership)