1. Error estimates for the numerical integration of ordinary differential equations (Russian), I;Lozinskii;Izv. Vysš. Ucebn. Zaved. Matematika,1958
2. Stability and Asymptotic Behavior of Differential Equations;Coppel,1965
3. Introduction to Functional Analysis;Taylor,1958
4. Foundations of Modern Analysis;Dieudonné,1960
5. Stability of Motion;Krasovskii,1963