Aidos, E. Zh., and M. Kaztay. “About the Relation Between the Best Approximations in Mixed Norms”. Journal of Mathematics, Mechanics and Computer Science 84, no. 1 (June 27, 2018): 3–7. Accessed December 22, 2024. https://bm.kaznu.kz/index.php/kaznu/article/view/418.