References
- Culpepper's Complete Herbal, Milner and Company, Manchester, 76–77
- Grieve M. A modern Herbal 1931; Vol. 2: 795, Jonathan Cape
- Hartwell J., Abbott B. Antineoplastic Principles in plants. Adv. in Pharmac. and Chemotherapy 1969; Vol. 7: 117–209
- Steinmetz E. F. Codex Vegetabilis, Amsterdam, Keizersgracht 1957; 347, Entry No. 323
- Korte F., Bechmann G. Naturwissenschaften 1958; Vol. 45: 390