George Ivanovich Gurdjieff
All and Everything, or Beelzebub's Tales to his
Grandson
Meetings with Remarkable Men
Life is Real Only Then, When "I am"
The Herald of Coming Harmony
Peter Demianovich Ouspensky
In Search of the Miraculous: Fragments of an
Unknown Teaching
The Fourth Way
The Strange Life of Ivan Osokin
Conscience: The Search for Truth
The Psychology and Cosmology of Man's Possible
Evolution
A New Model of the Universe
Tertium Organum
Rodney Collin-Smith
Theory of Celestial Influences
Theory of Conscious Harmony
The Theory of Eternal Life
The Mirror of Light
Robert Earl Burton
Self-Remembering
This list is by no means complete, but will give the seeker a good beginning.