Painter, Lynn, author
Simon & Schuster BFYR, 2021
Buku Teks
Estep, Tora, author
American Society for Training & Development, 2006
eBooks
Luecke, Richard A., author
American Management Association, 2008
eBooks
Burt, Angela, author
Stanley Thornes, 1995
Buku Referensi
Gramedia Pustaka Utama, 2013
Buku Teks