: variable exceptional point, nonlinear differential equation, analytical approximated solution, neighborhood of variable exceptional point, complex domain, a posteriori estimate.
V. N. Orlov, T. Yu. Leontieva, “On extension of the domain for analytical approximate solution of one class of nonlinear differential equations of the second order in a complex domain”, Vestn. Samar. Gos. Tekhn. Univ., Ser. Fiz.-Mat. Nauki [J. Samara State Tech. Univ., Ser. Phys. Math. Sci.], 24:1 (2020), 174–186
