Fan, Z. H. ., Y. L. . Hu, D. Z. . Ding, and R. S. . Chen. “A VSIE Solution for EM Scattering Using the Multilevel Complex Source Beam Method”. The Applied Computational Electromagnetics Society Journal (ACES), vol. 30, no. 11, Aug. 2021, pp. 1146-53, https://journals.riverpublishers.com/index.php/ACES/article/view/10323.