Grysa K, Leśniewska R, Maciąg A. Energetic approach to direct and inverse heat conduction problems with Trefftz functions used in FEM. Comp. Assist. Methods Eng. Sci. 2022;15(3-4):171-182. Accessed June 30, 2025. https://cames.ippt.pan.pl/index.php/cames/article/view/726