1. Almost periodic Schrödinger operators II. The integrated density of states,;J. Avron;Duke Math. Jour.,1983
2. On Dynamical Systems in the Space of Continuous Functions,;M. Bebutov;Bull. Inst. Mat. Moskov. Gos. Univ. 2 (1940).,1940
3. Theory of Ordinary Differential Equations,;E. Coddington;Mc Graw-Hill,1955
4. Dichotomies in Stability Theory,;W. Coppel;Lecture Notes in Mathematics,1978
5. The trace formula for Schrödinger operators on the line,;W. Craig;Comm. Math. Phys.,1989