M. C. Setzer, D. M. Moriarity, R. O. Lawton, W. N. Setzer, G. A. Gentry, and W. A. Haber, “Phytomedicinal potential of tropical cloudforest plants from Monteverde, Costa Rica”, Rev. Biol. Trop., vol. 51, no. 3-4, pp. 647–674, Dec. 2003.