@Article{Ince1926, author="E. L. Ince", title="Periodic solutions of a linear differential equation of the second order", journal="Proc. Cam. Philo. Soc.", year="1926", pages="44-46. ", volume="23" } @Article{Issic2007, author="K. C-L. Issic, P. N. Shivakumar ", title="On the eigenvalue problem \(-y''+f(x)y = \lambda y\) on a semi infinite interval", journal="Mathematical and Computer Modelling", year="2007", pages=" 316-330. ", volume="46" } @Book{Farés2009, author="A. Farés", title="Contribution à l'étude des opérateurs dans des espaces de suites et applications à l'optimisation et aux systèmes différentiels", year="2009", publisher="PhD thesis, University of Le Havre", address="France " } @Article{Malafosse2002, author="B. de Malafosse", title="Recent results in the infinite matrix theory and application to Hill equation", journal="Demonstratio Matematica", year="2002", pages=" 11-26. ", volume="35" } @Article{Malafosse2006, author="B. de Malafosse", title="An application of the infinite matrix theory to Mathieu equation ", journal="Comput. Math. Appl. ", year="2006", pages="1439-1452. ", volume="52" } @Article{Okutoyi 1992, author="J. T. Okutoyi ", title="On the spectrum of \(C_1\) as operator on bv", journal="Commun. Fac. Sci. Univ. Ank. Series A1", year="1992", pages="197-207. ", volume="41" } @Book{Poincaré 1886, author="H. Poincaré ", title="Sur les déterminants d'ordre infini", year="1886", publisher="Bull. Soc. Math. Fr., 14,87", address="" } @Article{Reade1985, author="J. B. Reade", title="On the spectrum of the Cesàro operator", journal="Bull. London Math., Soc. ", year="1985", pages=" 263-267. ", volume="17" } @Book{Rosseto 1983, author="B. Rosseto ", title="Détermination des exposants de Floquet de l'équation de Hill d'ordre n", year="1983", publisher="Thèse de Doctorat d'Etat Es-Sciences", address="Univ. Toulon" } @Article{Valeev1960, author="K. G. Valeev", title="On Hill's method in the theory of linear differential equations with periodic coefficients", journal="J. Appl. Math. Mech., transl. of Prikl. MAT.", year="1960", pages="1493-1505.", volume="24" }