1. Inverse Sturm-Liouville problems;Levitan,1984
2. The Theory of Generalized Translation Operators;Levitan,1973
3. Sturm-Liouville Operators and Their Applications;Marchenko,1977
4. Equations differentielles operationelles;Lions,1961
5. Transmutation Operators and Mean Periodic Functions Associated with Differential Operators;Trimeche,1988