K. Grysa, R. Leśniewska, and A. Maciąg, “Energetic approach to direct and inverse heat conduction problems with Trefftz functions used in FEM”, CAMES, vol. 15, no. 3-4, pp. 171–182, Jul. 2022, Accessed: Apr. 19, 2025. [Online]. Available: https://cames3.ippt.pan.pl/index.php/cames/article/view/726