1. On a characteristic class entering in a quantum condition;Arnold;Funct. Anal. Appl.,1967
2. Discrete and Continuous Boundary Problems;Atkinson,1964
3. Disconjugacy;Coppel,1971
4. Dichotomies in Stability Theory;Coppel,1978
5. Stability of Solutions of Differential Equations in Banach Space;Daleckii,1974