Sergey Yakovlevich Startsev, “On Darboux non-integrability of Hietarinta equation”, Ufimsk. Mat. Zh., 13, no. 2, 2021, 160
S. Ya. Startsev, “Symmetry Drivers and Formal Integrals of Hyperbolic Systems”, J Math Sci, 252, no. 2, 2021, 232
Giorgio Gubbiotti, “Algebraic entropy for systems of quad equations”, Open Communications in Nonlinear Mathematical Physics, Special Issue in Memory of..., 2024, 11638