1. D. J. Mabberlay, The Plant Book. A Portable Dictionary of the Vascular Plant. 2nd edition. Cambridge University Press, Cambridge, 1997.
2. J. L. Hartwell, Plants Used against Cancer, Quarterman publication Inc. Lawrence, Massachusetts, 1982, pp. 247–275.
3. J. A. Duke, Handbook of Medicinal Herbs, CRC press, Florida, 1986, p. 457.
4. N. Diklic, Flora SR Serbia, ed. M. Josifovic, SANU, Belgrade, 6, 1974, pp. 408–432.
5. P. W. Ball, Flora Europaea, eds. T. G. Tutin, V. H. Heywood, N. A. Burges, D. M. Moore, D. H. Valentine, S. M. Walters, and D. A. Webb, Cambridge University Press, Cambridge, 3, 1972, pp. 151–157.