1. “Functional Analysis,”;Bachman,1966
2. Functional analysis, nonlinear differential equations, and the alternative method;Cesari,1976
3. Cesari, L., An abstract existence theorem across a point of resonance, Dynamical Systems, an International Symposium at the Univ. of Florida (A. R. Bednarek and L. Cesari, eds.), Academic Press, (1977), pp. 11–26.
4. Nonlinear oscillations across a point of resonance for nonselfadjoint systems;Cesari;Journ. Differential Equations,1978
5. Nonlinear Analysis, a point of resonance for nonselfadjoint systems;Cesari,1978