Botanical.com - A Modern Herbal
- Actions, indications, habitat and preparation of hydrastis canadensis - Golden Seal.
- http://www.botanical.com/botanical/mgmh/g/golsea27.html

Goldenseal
- Information about the modern and traditional uses of this herb, including discussions of the conditions it is used to treat.
- http://www.solsticepoint.com/golden.htm

Nutrimart: Goldenseal
- Information about the active substances in this herb, its traditional uses, physiology, dosage, toxicity, and other advice.
- http://www.nutrimart.com/Bulk/Description/goldense.htm