According to the "Encyclopedia of Women And Religion in North America", several leaders of New Age philosophy have further developed Bailey's teachings, including the well-known personalities JZ Knight (who channels the entity known by the name Ramtha), Helen Schucman (author of A Course in Miracles through the process of telepathic dictation she called "scribing"), and Elizabeth Clare Prophet (who published what she referred to as "dictations from Ascended Masters"). These developments have been referred to by other sources as "spin-offs" and splinter groups." (p. 65) (p. 557) The differences between Theosophy, Bailey and Elizabeth Clare Prophet can be noted in connection with Elizabeth Clare Prophet's radical concepts of catastrophic change and survivalism, including the building of fall-out shelters. (p. 81) The validity of the Elizabeth Clare Prophet's writings was "...disputed by Theosophical writers".