Garden of Eden: The Shamanic Use of Psychoactive Flora and Fauna, and the Study of Consciousness by Snu Voogelbreinder

The Encyclopedia of Psychoactive Plants: Ethnopharmacology and Its Applications by Christian Rätsch

[epub version]

Plants of the Gods: Their Sacred, Healing, and Hallucinogenic Powers by Richard Evans Schultes, Albert Hofmann, Christian Rätsch

Cunningham's Encyclopedia of Magical Herbs by Scott Cunningham

[epub version]