1. P. Font Quer, Plantas Medicinales. El Dioscorides Renovado, 12th ed., Labor. S.A., Barcelona, 1990, p. 608.
2. M. Pahlow, Das grobe Buch der Heilpflanzen, Grafe und Unzer Verlag GmbH, Munchen, 2001.
3. P. C. Stevenson, M. S. J. Simmonds, J. Sampson, P. J. Houghton, and P. Grice, Phytother. Res., 16, 33 (2002).
4. R. Hansel and O Sticher, Pharmakognosie. Phytopharmazie, 7th ed., Springer Verlag, Berlin-Heidelberg-New York, 2004, p. 735.
5. K. Sesterhenn, M. Distl, and M. Wink, Plant Cell. Rep., 26, 365 (2007).