Na, P. T. L., V. C. Thang, N. M. Khoa, N. P. Thao, N. A. Duc, L. X. Dai, and T. H. Phong. “Research on Oil Dispersant Preparation from Synthetic Surfactants Suitable for Vietnamese Crude Oil”. Petrovietnam Journal, Vol. 3, Mar. 2015, pp. 40-50, http://www.pvj.com.vn/index.php/TCDK/article/view/443.