·Keepers of the ancient knowledge ·Ayahuasca: The Visionary and Healing Powers of the Vine of the Soul ·Masters of the living energy -Joan Wilcox
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·Sacred Vine of Spirits ·Teonanácatl: Sacred Mushrooms of Visions ·Allies for Awakening Guidelines for Productive and Safe Experiences with Entheogens -Ralph metzner
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·Psychedelic Healing: The Promise of Entheogens for Psychotherapy and Spiritual Development
-Neal m. Goldsmith
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Psychedelics Encyclopedia
Peter Stafford
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Just a few more recommendations, Jeremy narby had some good books, Dale Pendell's Pharmako trilogy is pretty good.
Honestly there is no shortage of information on the topic, though Richard Evans schultes, Christian ratsch, Jon ott, Gordon wasson, Albert Hoffman, Alexander shulgin, terence mckenna, just to name a few have always been my favorites...
-eg