1. Bradley PR (ed). British Herbal Compendium, vol 1. Bournemouth, Dorset, UK: British Herbal Medicine Association, 1992, 126-7.
2. Foster S. 101 Medicinal Herbs. Loveland, CO: Interweave Press, 1998, 32-3.
3. Schulz V, Hänsel R, Tyler VE. Rational Phytotherapy: A Physician's Guide to Herbal Medicine. 3rd ed, Berlin: Springer, 1998, 168-73.
4. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin: American Botanical Council and Boston: Integrative Medicine Communications, 1998, 425-6.
5. Lust JB. The Herb Book. New York: Bantam Books, 1974, 343.
6. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 92.