1. Impulsive Differential Equations;Bainov,1989
2. Stability and Asymptotic Behaviour of Differential Equations;Coppel,1965
3. Dichotomies in Stability Theory;Coppel,1978
4. C. Corduneanu, Almost Periodic Functions, 2nd edition, Chelsea-New York 1989
5. Integral Equations and Applications;Corduneanu,1991