Nine Star Ki: Michio Kushi's Guidebook on Love and Relationships, Health and Travel and Getting Through the 1990's THIS IS AN EXCELLENT INTRODUCTORY BOOK AND A VALUABLE ONGOING REFERENCE. IT IS HIGHLY RECOMMENDED. UNFORTUNATELY, IT IS OUT OF PRINT. CHECK FOR AVAILABILITY.
Secrets of Japanese Astrology: The Science of Kigaku Excellent, inexpensive but VERY hard to find. A very interesting and enjoyable introduction to 9 Star Ki.
The Enneagram: Understanding Yourself and the Others In Your Life The Enneagram clearly shares ancestral roots with 9 Ki Study and is, therefore, included here.
The Nine Ki Handbook: An Updated Guide to Nine Star Ki Astrology The first 9 Star Ki book in English. Get one if you can.