Nguyen Huu Dong, Nguyen Ba Tuong, & Nguyen Duc Tho. (2020). ALGORITHMS FINDING REDUCTIONS FOR A SINGLE AND A SET-VALUE INFORMATION SYSTEM USING THE CONCEPT OF POSITIVE REGION. UTEHY Journal of Science and Technology, 10, 65-68. Retrieved from http://tapchi.utehy.edu.vn/index.php/jst/article/view/284