Books written specifically about the ORMUS materials:

The Alchemy Key
Stuart Nettleton

The Pillar of Celestial Fire
Robert Cox

Genesis of the Grail Kings
Laurence Gardner

Lost Secrets of the Sacred Ark
Laurence Gardner

Books referenced by David Hudson

Sacred Science
R. A. Schwaller de Lubicz

Le Mystere des Cathedrales (The Mysteries of the Cathedrals)
Fulcanelli (translated from the French by Mary Sworder)

Quantum Self: Human Nature and Consciousness Defined by the New Physics
Danah Zohar

Stalking the Wild Pendulum: On the Mechanics of Consciousness
Itzhak Bentov

Ages in Chaos
Immanuel Velikovsky

My recommendations

Occult Chemistry
C. W. Leadbeater & Annie Besant

Extra-Sensory Perception of Quarks
Stephen M. Phillips, Ph.D.

The Red Lion
Maria Szepes
Review by Dennis Waterman

Paramagnetism - Rediscovering Nature's Secret Force of Growth
Philip S. Callahan, Ph.D.

Ancient Mysteries, Modern Visions
Philip S. Callahan, Ph.D.

Secrets of the Soil
Peter Tompkins & Christopher Bird

The Jewish Alchemists
Raphael Patai

The Field
Lynne McTaggart
Review by Barry Carter

Bridging Science and Spirit - Common Elements in David Bohm's Phyusics, the Perennial Philosophy and Seth
Norman Friedman