Jacques Fabrice Vallée is a venture capitalist, computer scientist, author, and former astronomer.

Terence Kemp McKenna was an American ethnobotanist, mystic, psychonaut, lecturer, author, and was an advocate for the responsible use of naturally occurring psychedelic plants.

John Edward Mack M.D. was an American psychiatrist, writer, and professor at Harvard Medical School. He was a Pulitzer Prize-winning biographer, and a leading authority on the spiritual or transformational effects of alien abduction experiences.

Elliot Budd Hopkins was an American painter, sculptor, and prominent figure in alien abduction phenomena and related UFO research.

Source: A Mysterious Universe