- Author: Lecouteux Claude
- Language: English
- Year: 2015
- Author: Lecouteux Claude
- Language: English
- Year: 2015
- Author: Lecouteux Claude
- Language: English
- Year: 2015
- Author: Hanegraaff Wouter J
- Language: English
- Year: 2014
- Author: Gurdjieff Georges Ivanovitch, Uspenskiĭ Petr Demʹi︠a︡novich, Lachman Gary
- Language: English
- Year: 2006
- Author: Dodds Eric R
- Language: English
- Author: Hall Manly Palmer, Knapp J. Augustus
- Language: English
- Year: 2003
- Author: Kelly Aidan A
- Language: English
- Year: 2011
- Author: Asprem Egil
- Language: English
- Year: 2012
- Author: Asprem Egil.Project Muse
- Language: English
- Year: 2012