Necessary and sufficient conditions for the nonlinear difference operator $(Dx)(t) = x(t + 1) - f(x(t))$ to be invertible in the space of functions bounded and continuous on the axis. НК. 2002;5(3):380-386. Accessed January 22, 2026. https://twinhead.imath.kiev.ua/index.php/nosc/article/view/228