Juraev, D. A. ., A. . Shokri, P. . Agarwal, E. E. . Elsayed, and I. . Nurhidayat. “Approximate Solutions of the Helmholtz Equation on the Plane”. Engineering Applications, vol. 2, no. 3, Nov. 2023, pp. 291-03, https://publish.mersin.edu.tr/index.php/enap/article/view/1179.