1. L.A.D. Williams, H. Rösner, J. Conrad, W. Möller, U. Beifuss, K. Chiba, J.P. Nkurunziza, W. Kraus, Rec. Res. Devel. Phytochem. 6, 13–68 (2002)
2. G. Jolliffe, British Homeopath J. 71, 31–34 (1982)
3. G. Ravikiran, A.B. Raju, Y. Venugopal, Int. J. Res. Pharm. Biomed. Sci. 2, 942–946 (2011)
4. A. Lemma, Bull. World Health Org. 42, 597–612 (1970)
5. J.D.H. Lambert, L. Wolde-Johannas, L. Makhubu, Bioscience 35, 364–366 (1985)