Denysenko, N. L., and A. M. Samoilenko. “On Solutions of Linear Functional Differential Equations With Linearly Transformed Argument on a Semiaxis”. Ukrains’kyi Matematychnyi Zhurnal 59, no. 4 (April 25, 2007): 501–513. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/3324.