1. Functional analysis and periodic solutions of nonlinear differential equations;Cesari;Contrib. Differential Equations,1963
2. Functional analysis and Galerkin's method;Cesari;Michigan Math. J.,1964
3. L. Cesari, Alternative methods in nonlinear analysis. In Internat. Conf. Differential Equations, (H. Antosiewicz, ed.), pp. 95–148. Academic Press, New York, 1975
4. L. Cesari, Nonlinear oscillations in the frame of alternative methods. In Internat. Conf. Dynamical Systems, (L. Cesari, J. Hale, and J. LaSalle, eds.), pp. 29–50. Academic Press, New York, 1976.
5. Functional analysis and nonlinear differential equations;Cesari,1976