Gwandu, U. Z., S. M. Dangoggo, U. Z. Faruk, E. M. Halilu, A. J. Yusuf, and M. M. Mailafiya. “Isolation and Characterization of Oleanolic Acid Benzoate from the Ethylacetate Leaves Extracts of Vernonia Ambigua (Kotschy Ex. Peyr) ”. Journal of Chemical Society of Nigeria 45, no. 5 (August 30, 2020). Accessed June 20, 2021. https://journals.chemsociety.org.ng/index.php/jcsn/article/view/518.