Agus Pakpahan
BRI, 2004
Buku Teks SO
Avanti Fontana
2006
Artikel Jurnal
edited by Zacharoula Andreopoulou, Vagis Samathrakis, Soulla Louca, Maro Vlacopoulu
Igi Global, 2014
Buku Teks
Hattori, Ruth Ann
[American Society for Training and Development Press;;;, ], 2004
eBooks
Nystrom, Harry
John Wiley & Sons, 1979
Buku Teks