Akishev, G., and A.Kh. Myrzagaliyeva. “On Estimates of M-Term Approximations of the Sobolev Class in the Lorentz Space”. Bulletin of the Karaganda University. Mathematics Series 114, no. 2 (June 28, 2024): 4–21. Accessed August 25, 2025. http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/743.