Bak, S.M., and G. M. Kovtonyuk. “Well-Posedness of the Cauchy Problem for System of Oscillators on 2D–lattice in Weighted $l^2$-Spaces”. Matematychni Studii 56, no. 2 (December 27, 2021): 176-184. Accessed July 18, 2024. http://matstud.org.ua/ojs/index.php/matstud/article/view/182.