Khamchane, Abdelkader, Youcef Khelfaoui, and Brahim Hamtache. 2017. “Shape Optimization of Reactive Mufflers Using Threshold Acceptance and FEM Methods”. Canadian Acoustics 45 (2):25-36. https://jcaa.caa-aca.ca/index.php/jcaa/article/view/3034.