Kołodziej, J. A., & Uściłowska, A. (2023). Trefftz-type procedure for Laplace equation on domains with circular holes, circular inclusions, corners, slits, and symmetry. Computer Assisted Methods in Engineering and Science, 4(3-4), 501-519. https://cames3.ippt.pan.pl/index.php/cames/article/view/1386