Бейсебай, П., and Ғ. Мұхамедиев. “ON A METHOD FOR INTRODUCING THE CONCEPTS OF A NUMERICAL SERIES AND ITS CONVERGENCE”. Bulletin of Abai KazNPU. Series of Physical and Mathematical Sciences, vol. 80, no. 4, Dec. 2022, pp. 80-88, doi:10.51889/2511.2022.57.40.009.