Nhinh Nguyen Van, and Vi Nguyen Tuong. “ASSESSMENT OF THE QUALITY OF LUBRICATION OIL FOR USE ON LPG/DIESEL FUEL ENGINE”. UTEHY Journal of Science and Technology, Vol. 37, Mar. 2023, pp. 20-24, http://jst.utehy.edu.vn/index.php/jst/article/view/582.