GURDJIEFF / DE HARTMANN: COMPLETE MUSIC FOR THE PIANO - Klassiek.nl
Hartmann's operation - Wikipedia
The Gurdjieff Legacy Foundation Archives
On Olga de Hartmann
Why Has Ukranian Composer Thomas de Hartmann Been So Neglected?
Thomas de Hartmann (Composer, Arranger) - Short Biography
Thomas de Hartmann | Spotify
Thomas de Hartmann: A Composer's Life
Fabulous de Hartmann Premieres on Toccata from Kuchar and the Lviv Philharmonic - Classics Today
PDF) Gurdjieff and Music: The Gurdjieff/de Hartmann Piano Music and its Esoteric Significance | Johanna Petsche - Academia.edu
Thomas de Hartmann - Vrije Geluiden - VPRO
Why Has Ukranian Composer Thomas de Hartmann Been So Neglected?
Gurdjieff / De Hartmann – The Music Of Gurdjieff / De Hartmann (1985, Vinyl) - Discogs
Thomas De Hartmann Discography | Discogs
The Thomas de Hartmann Project
The Thomas de Hartmann Project
Why Has Ukranian Composer Thomas de Hartmann Been So Neglected?
Gurdjieff - De Hartmann Piano Music - YouTube
Why Has Ukranian Composer Thomas de Hartmann Been So Neglected?
Gurdjieff / De Hartmann: Complete Music for the Piano - YouTube
Olga und Thomas de Hartmann: Biografien | Chalice Verlag
The Chamber Music of Thomas de Hartmann by Elan Sicroff on Apple Music
