Dovhopiatyi , O. P., and E. A. Sevost’yanov. 2022. “On the Existence of Solutions of Quasilinear Beltrami Equations With Two Characteristics”. Ukrains’kyi Matematychnyi Zhurnal 74 (7), 961 -72. https://doi.org/10.37863/umzh.v74i7.7088.