“ Antitumor activity of leaves of Himatanthus drasticus (Mart.) Plumel-Apocynaceae (janaguba) in the treatment of Sarcoma 180 tumor ”, Braz. J. Pharm. Sci., vol. 46, no. 2, pp. 199–203, Jun. 2010, doi: 10.1590/S1984-82502010000200005.