1. Theory of Oscillators;Andronov,1966
2. Forced oscillations in second order systems with bounded nonlinearities;Benediktsson,1965
3. Forced oscillations in second order systems with bounded nonlinearities;Benediktsson,1967
4. Asymptotic Behavior and Stability Problems in Ordinary Differential Equations;Cesari,1963
5. Positivity and comparison results for nonlinear boundary value problems and related periodic solutions;Chandra;J. Math. Anal. Appl.,1968