Pham, Phong Van, and Hong Khanh Dieu Nguyen. “Study on Conversion of Vegetable Oil Deodorizer Distillate to Biodiesel Using Mesoporous Oxo-Phosphated Sulfated Zirconia”. Vietnam Journal of Science and Technology, vol. 55, no. 1, Feb. 2017, pp. 44-53, doi:10.15625/0866-708X/55/1/8116.