Sanecki, Henryk, and Andrzej P. Zieliński. “The Trefftz Finite Elements Modelling Crack Propagation”. Computer Assisted Methods in Engineering and Science 15, no. 3-4 (July 21, 2022): 353–368. Accessed April 19, 2025. https://cames3.ippt.pan.pl/index.php/cames/article/view/742.