Gardner-Gordon, Joy. Color and Crystals: A Journey through the Chakras. Feasterville-Trevose, PA: Crossing Press, 1988.
George, Demetra, and Douglas Bloch. Asteroid Goddesses: The Mythology, Psychology, and Astrology of the Re-Emerging Feminine. Revised ed. Lake Worth, FL: Nicolas-Hays, Inc., 2003.
Gibran, Kahlil. The Prophet. New York: Alfred A. Knopf, 1923.
Hickey, Isabel M. Astrology, A Cosmic Science: The Classic Work on Spiritual Astrology. Sebastopol, CA: CRCS Publications, 1979.
Hidell, Al, and Joan d’Arc. The New Conspiracy Reader: From Planet X to the War on Terrorism–What You Really Don’t Know. New York: Citadel Press, 2004. [Author’s Note: This book includes information about Marcel Vogel.]
Javane, Faith, and Dusty Bunker. Numerology and the Divine Triangle. Atglen, PA: Schiffer, 1979.
Lembo, Margaret Ann. The Angels and Gemstone Guardians Cards. Forres, UK: Findhorn Press, 2014.
———. Chakra Awakening: Transform Your Reality Using Crystals, Colors, Aromatherapy & the Power of Positive Thought. Woodbury, MN: Llewellyn Publications, 2011.
———. The Essential Guide to Crystals, Minerals and Stones. Woodbury, MN: Llewellyn Publications, 2013.
———. The Essential Guide to Aromatherapy and Vibrational Healing. Woodbury, MN: Llewellyn Publications, 2016.
Melody. Love Is in the Earth: A Kaleidoscope of Crystals. Wheat Ridge, CO: Earth Love Pub. House, 1991.
Milanovich, Dr. Norma, and Dr. Shirley McCune. The Light Shall Set You Free. Kalispell, MT: Athena Publishing, 1996.
Milewski, John and Virginia Harford, ed. The Crystal Sourcebook: From Science to Metaphysics. Santa Fe, NM: Mystic Crystal Publications, 1987. [Author’s Note: This book includes information about Marcel Vogel’s experiments with crystals.]
Neville, E. W. Planets in Synastry: Astrological Patterns of Relationships. Atglen, PA: Whitford Press, 1990.
Raphaell, Katrina. Crystal Enlightenment: The Transforming Properties of Crystals and Healing Stones. Santa Fe, NM: Aurora Press, 1985.
———. Crystal Healing: The Therapeutic Application of Crystals and Stones. Santa Fe, NM: Aurora Press, 1987.
———. The Crystalline Transmission: A Synthesis of Light. Santa Fe, NM: Aurora Press, 1989.
Raven, Hazel. The Secrets of Angel Healing: Therapies for Mind, Body and Spirit. London: Godsfield Press, 2006.
Sakoian, Frances, and Louis S. Acker. The Astrology of Human Relationships: Techniques for Guiding or Evaluating Your Personal, Social & Business Relationships. New York, NY: Harper & Row, 1973.
Snider, Jerry, and Richard Daub. “The Advocacy of Marcel Vogel.” Magical Blend: A Transformative Journey Magazine, 1986.
Stein, Diane. The Women’s Book of Healing: Auras, Chakras, Laying On of Hands, Crystals, Gemstones, and Colors. St. Paul, MN: Llewellyn Publications, 1986.
Taylor, Terry Lynn. Messengers of Light: The Angels’ Guide to Spiritual Growth. Tiburon, CA: HJ Kramer, 1989.
White Eagle. Spiritual Unfoldment 2: The Ministry of Angels and the Invisible World of Nature. 2nd ed. Camarillo, CA: White Eagle Pub. Trust, 2008.