Ngo, T., T. Nguyen, D. Bui, N. Hoang, and T. Nguyen. “Effects of Ricin Extracted from Seeds of the Castor Bean (ricinus Communis) on Cytotoxicity and Tumorigenesis of Melanoma Cells”. Biomedical Research and Therapy, Vol. 3, no. 05, May 2016, pp. 633-44, http://bmrat.biomedpress.org/index.php/BMRAT/article/view/97.