“Families of Lyapunov’s Functions for Existence of Almost Periodic Solutions of $( h_0,h)$-Stable Impulsive Differential Equations”. Nonlinear Studies 10, no. 2 (May 1, 2003). Accessed June 1, 2026. https://www.nonlinearstudies.com/index.php/nonlinear/article/view/157.