F. Ihlenburg and I. Babuška, “Solution of Helmholtz problems by knowledge-based FEM”, CAMES, vol. 4, no. 3-4, pp. 397–415, Jun. 2023, Accessed: Jan. 12, 2025. [Online]. Available: https://cames3.ippt.pan.pl/index.php/cames/article/view/1381