BITIMKHAN, S.; ALIBIEVA, D.T. Partial best approximations and the absolute Cesaro summability of multiple Fourier series. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 103, n. 3, p. 4–12, 2021. DOI: 10.31489/2021m3/4-12. Disponível em: http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/444. Acesso em: 24 aug. 2025.