D. S. Zhalukevich, “Equivalence transformations of families of se­cond-order quasi-linear hyperbolic equations of a two-variable function”, Журнал Белорусского государственного университета. Математика. Информатика, no. 2, pp. 28–38, Sep. 2026, Accessed: Nov. 11, 2026. Available: https://journals.bsu.by/index.php/mathematics/article/view/7305