[1]
M. B. Tahir and A. A. Aswhad, “On the Riesz Means of Expansions by Riesz Bases Formed by Eigenfunctions for the Ordinary Differential Operator of 4-th Order”, IHJPAS, vol. 22, no. 1, Aug. 2017, Accessed: Mar. 29, 2025. [Online]. Available: https://jih.uobaghdad.edu.iq/index.php/j/article/view/1277