Ohayon, R. ., and C. Soize. “Methodes Numeriques Avancees En Vibroacoustique Basses Et Moyennes Frequences”. European Journal of Computational Mechanics, vol. 8, no. 5-6, May 1999, pp. 607-3, https://journals.riverpublishers.com/index.php/EJCM/article/view/2991.