A.R. Khoei, S.O.R. Biabanaki, and R. Yasbolaghi. “A polygonal–FEM Technique in Modelling Arbitrary Interfaces on Non-Conformal Meshes: A Study on Polygonal Shape Functions”. European Journal of Computational Mechanics, vol. 23, no. 1-2, Feb. 2014, pp. 15-37, https://journals.riverpublishers.com/index.php/EJCM/article/view/1337.