Kairbekov, Zhaksyntay, Ermek Aubakirov, and Nazym Smagulova. “Preparation of Bitumen from Charkchemical Tar by Catalytic Oxidation and Study of Its Structure and Properties”. Chemical Bulletin of Kazakh National University 68, no. 4 (December 4, 2012): 56-63. Accessed April 3, 2025. https://chemistry.kz/bulletin/index.php/kaznu/article/view/274.