Muhammad Iqbal, author
Fakultas Psikologi Universitas Indonesia, 2004
UI - Tesis Membership
Edo Setyadi, author
2016
UI - Skripsi (Membership)
Djati Sutomo, author
Republika, 2007
Buku Teks
Chalofsky, Neal, author
American Society for Training & Development Press, 2001
eBooks
Berry, Brewton, author
Houghton-Miffiln, 1958
Buku Teks