Lukovsky IO, Timokha AN. Variational formulations of nonlinear boundary-value problems with a free boundary in the theory of interaction of surface waves with acoustic fields. Ukr. Mat. Zhurn. [Internet]. 1993Dec.25 [cited 2024Jul.27];45(12):1642–1652. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/5972