Richardson, Niall, author
Routledge, 2014
Buku Teks
Nourse, Alan E.
Time Incorporated, 1964
Buku Referensi
Mcevoy, Sean, author
Routledge, 2006
Buku Teks
Russell, Jeffrey, author
American Society for Training & Development, 2006
eBooks
Haneberg, Lisa, author
American Society for Training & Development, 2006
eBooks