Pham Ngoc Thang, and Bui Thi Kim Thoa. “ERROR REDUCTION IN MEASUREMENT DEVICE OF SUBTRACTION OF TWO NON-ELECTRIC QUANTITIES BY STRUCTURE OF TWO TIMES INTERGAL METHOD”. UTEHY Journal of Science and Technology, Vol. 37, Mar. 2023, pp. 73-78, http://tapchi.utehy.edu.vn/index.php/jst/article/view/590.