Heelas, Paul
Blackwell, 2005
Buku Teks SO
Krishnamurti
Komunitas Krishnamurti Indonesia, 2009
Buku Teks SO
Artikel Jurnal
Al-Qarni, Aidh Abdullah
Qisthi Press, 2004
Buku Teks SO
editor, Martin L. Sinaga
Gramedia Widiasarana Indonesia, 2000
Buku Teks SO