Wilwood, Chrissie
The Encyclopedia of Healing Plants : A Complete Guide to Aromatherapy, Flower Essences and Herbal Remedies
Piatkuss, 1998
 Buku Teks
Murray, Michael T.
Encyclopedia of Nutritional Supplements : The Essential Guide for Improving Yur Health Naturally
Three Rivers Press, 1996
 Buku Teks
Lenk, John D.
McGraw-Hill Circuit encyclopedia and troubleshooting guide; Volume 3
McGraw-Hill, 1993
 Buku Referensi
The World book encyclopedia : volume 20, reading and study guide
Field Enterprises Educational Corporation, 1963
 Buku Referensi
Managing interdisciplinary research
John Wiley & Sons, 1983
 Buku Teks SO