Ke, H. ., and T. H. . Hubing. “A Modified LU Recombination Technique for Improving the Performance of Boundary Element Methods at Low Frequencies”. Applied Computational Electromagnetics Society Journal (ACES), vol. 20, no. 3, June 2022, pp. 178-85, https://journals.riverpublishers.com/index.php/ACES/article/view/16601.