Tran, Van-Nghi, Nang-Tam Nguyen, and Chi-Thanh Le. “On Minimization of Quadratic Functions over Closed Convex Sets in Hilbert Spaces”. HPU2 Journal of Science: Natural Sciences and Technology 3, no. 3 (December 30, 2024): 70–79. Accessed January 7, 2025. http://sj.hpu2.edu.vn/index.php/journal/article/view/265.