BarannykA. F., BarannikL. F. and FushchichV. I. (1994) “Reduction of the multidimensional d’Alembert equation to two-dimensional equations”, Ukrains’kyi Matematychnyi Zhurnal, 46(6), pp. 651–662. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5692 (Accessed: 6October2024).