Vuković, M., Ilić-Georgijević, E., & Stevanović, O. (2024). On an Application of Parseval’s Formula to Problems of $G_\theta^\varkappa$-summability of Eigenfunction Expansion of the Laplacian Operator. Sarajevo Journal of Mathematics, 12(2), 267–276. https://doi.org/10.5644/SJM.12.2.12