Fokialakis, N. Kalpoutzakis, E. Tekwani, B.L. Skaltsounis, A.L. Duke, S.O., Antileishmanial activity of natural diterpenes from Cistus sp. and semisynthetic derivatives thereof, Biological and Pharmaceutical Bulletin, (29), 1775-1778, 2006, 0918-6158, 1347-5215