Salimov , R. R., and M. V. Stefanchuk. “Logarithmic Asymptotics of the Nonlinear Cauchy – Riemann – Beltrami Equation”. Ukrains’kyi Matematychnyi Zhurnal 73, no. 3 (March 19, 2021): 395–407. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/6403.