Akishev, G. “Estimations of the Best M-Term Approximations of Functions in the Lorentz Space With Constructive Methods”. Bulletin of the Karaganda University. Mathematics Series 87, no. 3 (September 29, 2017): 13–26. Accessed July 10, 2025. https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/158.