Johnson, Spencer, author
Elex Media Komputindo, 2004
Buku Teks
Johnson, Spender, author
Elex Media Komputindo, 2004
Buku Teks
Hariyanto Abdul Jalal
Jakarta RajaGrafindo Persada 2000,
Buku Teks
Yeni Febrianti Kumala Dewi, author
Fakultas Psikologi Universitas Indonesia, 2005
UI - Tesis Membership
Heyn, Dalma
New York Villard 1997,
Buku Teks