Uściłowska, Anita, and Jan A. Kołodziej. “Solution of the Nonlinear Equation for Isothermal Gas Flows in Porous Medium by Trefftz Method”. Computer Assisted Methods in Engineering and Science, vol. 13, no. 3, Nov. 2022, pp. 445-56, https://cames3.ippt.pan.pl/index.php/cames/article/view/945.