V. G. Abdrakhmanov, E. F. Saprykin, Yu. N. Smolin, “On the stability of the solution of the Cauchy problem for a periodic functional-differential equation with distributed delay”, Izv. Vyssh. Uchebn. Zaved. Mat., 2001, no. 6, 3–11; Russian Math. (Iz. VUZ), 45:6 (2001), 1–9
