Escaig, Y. ., M. . Vayssade, and G. . Touzot. “Une Methode De Decomposition De Domaines Multifrontale Multiniveaux”. European Journal of Computational Mechanics, vol. 3, no. 3, Mar. 1994, pp. 311-37, https://journals.riverpublishers.com/index.php/EJCM/article/view/3609.