I just finished reading Etheric Anatomy: the Three Selves and Astral Travel by Victor and Cora Anderson. Victor and Cora were the founders of Feri Witchcraft. It's a very good book, if a little strange. I'm glad I read it.
The first section is Victor's description of the three souls. The second section is Cora's description of the three souls, the Ha Prayer and Kala, and of out-of-body experiences. The final section is Victor's description of Astral sex. That is the strange part.
The book gives the most detailed description of the three souls that I've ever read, whether in Feri or in Kabbalah. It's a great description and one everyone should read.