Very helpfull to understand astral projection
There is two part from this book. Part One about history. Shamanism, fairy kingdom, spiritism, theosophy, golden dawn, remote viewing and UFO abduction. Part Two about the practice. Ritual Magic, Astral Doorways, Using Tarot, Preparation (physic and mental). You can skip part one if you like to learn or compare the methods. Tyson believe that astral travel occurs in our mind. There is no actual separation astral body from physical body. I agree with him. Buy and read this book, you won't regret it.