Sitorus, Roy Tulus Martin, author
Program Pascasarjana Universitas Indonesia, 2005
UI - Tesis (Membership)
McLeod, John, author
Kencana, 2003
Buku Teks
Lubis, Namora Lumongga, author
Kencana Prenada Media Group, 2011
Buku Teks
Tritana Gondhoyoewono, author
1991
UI - Tesis (Membership)
Teszy Mira Ekakusuma, author
Fakultas Psikologi Universitas Indonesia, 2004
UI - Tesis (Membership)