Petri Alfonsi DialogusPetrus Alfonsi, Carmen Cardelle de Hartmann, Darko Senekovic, Thomas Ziegler · First published 2018Open the Tome
Nuestra vida con el señor GurdjieffThomas De Hartmann, Olga De Hartmann, Consejo Editorial de Ganesha, Fundación G. I. Gurdjieff Caracas · First published 2014Open the Tome
Our Life with Mr. GurdjieffThomas de Hartmann, Olga de Hartmann · First published 1964 · Latest edition 1972Open the Tome
