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2. British Herbal Pharmacopoeia (BHP) (1976) Exeter: British Herbal Medicine Association
3. Bruneton J (1999) Pharmacognosy, phytochemistry, medicinal plants, 2nd edn. Intercept Ltd, London
4. Consolidated Directive 2001/83/EC of the European Parliament and of the Council of 6 November 2001 on the community code relating to medicinal products for human use as amended by Directive 2002/98/EC, Directive 2003/63/EC, Directive 2004/24/EC, Directive 2004/27/EC and Directive 2008/29/EC
5. Directive 2004/24/EC of the European Parliament and of the Council of 31 March 2004 amending, as regards traditional herbal medicinal products, Directive 2001/83/EC on the community code relating to medicinal products for human use