S. Ya. Startsev, “Symmetry Drivers and Formal Integrals of Hyperbolic Systems”, J Math Sci, 252, no. 2, 2021, 232
I T Habibullin, A R Khakimova, M N Poptsova, “On a method for constructing the Lax pairs for nonlinear integrable equations”, J. Phys. A: Math. Theor., 49, no. 3, 2016, 035202
S. Ya. Startsev, “Differential substitutions of the miura transformation type”, Theor Math Phys, 116, no. 3, 1998, 1001
Martin Juráš, Ian M. Anderson, “Generalized Laplace invariants and the method of Darboux”, Duke Math. J., 89, no. 2, 1997
Kostyantyn Zheltukhin, Natalya Zheltukhina, “Semi-discrete hyperbolic equations admitting five dimensional characteristic x-ring”, JNMP, 23, no. 3, 2021, 351
Handbook of Nonlinear Partial Differential Equations, Second Edition, 2011, 1795
S Ya Startsev, “Relationships between symmetries depending on arbitrary functions and integrals of discrete equations”, J. Phys. A: Math. Theor., 50, no. 50, 2017, 50LT01
Peter J. Olver, 3519, Computer Algebra and Geometric Algebra with Applications, 2005, 105
Сергей Петрович Царев, Sergey Petrovich Tsarev, “Факторизация линейных дифференциальных операторов с частными производными и метод Дарбу интегрирования нелинейных уравнений с частными производными”, ТМФ, 122, no. 1, 2000, 144
Ian M. Anderson, Niky Kamran, “The variational bicomplex for hyperbolic second-order scalar partial differential equations in the plane”, Duke Math. J., 87, no. 2, 1997