The well-known I Ching was originally only one of several works that formed the Ta Pu, the Grand Oracle. It has long been thought that the I Ching's companions had been destroyed, but now, after 2000 years, one of those lost works, through the T'ai Hsuan Ching has been rescued from oblivion.
Derek Walters is a leading authority on the history and practice of Chinese astrology. His lectures take him around the world, and he has written a number of successful books, including The Secrets of Chinese Astrology and The Feng Shui Handbook.