OTOIKHIAN, S. K., E. O. ALUYOR, and T. O. K. AUDU. “Two-Steps Transesterification of Hura Crepitans Seed Oil Using Polymer Based Catalyst”. Walailak Journal of Science and Technology (WJST), vol. 13, no. 11, May 2016, pp. 931-7, https://wjst.wu.ac.th/index.php/wjst/article/view/1761.