Internet sources:
Britannica OnLine (www.Britannica.com)
Merriam-Webster OnLine (www.m-w.com)
Stanford Encyclopedia of Philosophy (plato.stanford.edu)
Microsoft Encarta (http://encarta.msn.com)
Printed sources:
Everything is Under Control
© 1998 by Robert Anton Wilson (author), HarperCollins Publishers, Inc. (publisher).
Harper's Enclclopedia of Mystical & Paranormal Experience
© 1991 by Rosemary Ellen Guiley (author), Castle Books (publisher).
Religion of the World, Sixth Edition
© 1994 by Prentice-Hall, Inc. (publisher), Lewis M. Hopfe (author).