On Olga de Hartmann
Thomas de Hartmann - Wikipedia
Thomas de Hartmann (Composer, Arranger) - Short Biography
Thomas de Hartmann: A Composer's Life
Gurdjieff / De Hartmann – The Music Of Gurdjieff / De Hartmann (1985, Vinyl) - Discogs
Thomas de Hartmann | Spotify
Thomas de Hartmann (Composer, Arranger) - Short Biography
Thomas de Hartmann (1885-1956) : "Rituals of a Sufi Order" piano (3 extracts) - YouTube
Thomas de Hartmann (Composer, Arranger) - Short Biography
Thomas de Hartmann | Spotify
Thomas de Hartmann - Vrije Geluiden - VPRO
Fabulous de Hartmann Premieres on Toccata from Kuchar and the Lviv Philharmonic - Classics Today
Hartmann's operation - Wikipedia
Thomas de Hartmann | Spotify
Gurdjieff / De Hartmann – The Music Of Gurdjieff / De Hartmann (1985, Vinyl) - Discogs
The Gurdjieff Legacy Foundation Archives
Thomas de Hartmann Project - Home | Facebook
Thomas de Hartmann: Orchestral Music | Toccata Music Group | Toccata Classics | Toccata Press | Toccata Next
The Music of GURDJIEFF / de HARTMANN Hymns, Prayers and Dances - YouTube
