•  Aromatherapy & Subtle Energy Techniques
   by Jonie Keim Loughran & Ruah Bull.  For understanding energy healing, and energetic properties of the essential oils.

• • The Blossoming Heart
   by Robbi Zeck ND  Many healing insights, she brings Transformation Kinesiology together with essential oils.  Emotional Barometer chart. 
  • Also, books by Kurt Schnaubelt, Valerie Worwood, Penny Price,  Valerie Cooksly, Jane Buckle

• The Complete Guide to Aromatherapy  $62.00                  By Salvatore Battaglia  Second Edition  ISBN0 646 20670 2  - this is the best all round textbook for professional use.

• • The Encyclopedia of Aromatherapy   $25.00          By Chrissie Wildwood ISBN 0-89281-638-4  - Another option, less info but still covers wide range of topics, well rounded.

• • Aromatherapy for Healing the Spirit
   by Gabriel Mojay A Guide to Restoring Emotional and Mental Balance Through Essential Oils. Excellent for understanding oils from the emotional spiritual connection, also he relates oils to the Chinese 5 elements theories