Periodic solutions for a class of Li\'enard equations

1 Arino, O.; Cherif, A. A. On the Existence of Periodic Solutions for a Class of Nonlinearly Forced Systems Funkc. Ekvac. 35 1992 485-503 MR1199469 1199469

2 Bahri, A.; Berestycki, H. Existence of Forced Oscillations for Some Nonlinear Differential Equations Comm. Pure Appl. Math. 37 1984 403-442 MR0745324

3 Burton, T. A.; Townsend, C. G. On the Generalized Liénard Equation with Forcing Term J. Differential Equations 4 1968 620-633 MR0232042

4 Capietto, A.; Mawhin, J.; Zanolin, F. A Continuation Approach to Superlinear Boundary Value Problems J. Differential Equations 88 1990 347-395 MR1081252

5 Conti, R. Soluzioni Periodiche dell'Equazione di Liénard Generalizzata. Esistenza ed Unicita Boll. Un. Mat. Ital. 3 1952 111-118 MR0051998

6 Dieckerhoff, R.; Zender, E. Boundedness of Solutions via the Twist-Theorem Ann. Scuola Norm. Sup. Pisa, Cl. Sci. 14 1987 79-95 MR0937537

7 Ding, W. Fixed Points of Twist Mappings and Periodic Solutions of Ordinary Differential Equations Acta Math. Sinica 25 1982 227-235 (Chinese) MR0677834

8 Ding, T.; Zanolin, F. Periodic Solutions of Duffing's Equations with Superquadratic Potential J. Differential Equations 97 1992 328-378 MR1167538

9 Filippov, A. F. Sufficient Conditions for the Existence of Stable Limit Cycles of Second Order Equations Mat. Sb. 30(72) 1952 171-180 (Russian) MR0047869

10 Graef, J. R. On the Generalized Liénard Equation with negative Dumping J. Differential Equations 12 1972 34-72 MR0328200

11 Hale, J. K. Ordinary Differential Equations Pure and Applied Mathematics, Vol XXI, Robert E. Krieger Publishing Company, Inc. 1980 MR0419901 12 Hara, T.; Yoneyama, T. On the Global Center of Generalized Liénard Equation and Its Application to Stability Problems Funkcial. Ekvac. 28 1985 171-192 MR0816825 0816825

13 Hartman, P. On Boundary Value Problems for Superlinear Second order Differential Equations J. Differential Equations 26 1977 37-53 MR0477242

14 Liu, B. Existence of Subharmonic Solutions of Any Order of a Nonconservative System Adv. in Math. (China) 20 1991 103-108 MR1106724

15 Liu, B. An Application of KAM Theorem of Reversible Systems Sci. China Ser. A 34 1991 1068-1078 MR1160743

16 Liu, B.; You, J. Quasiperiodic Solutions for Nonlinear Differential Equations of Second Order with Symmetry Acta Math. Sinica, New Series 10 1994 231-242 MR1415694

17 Mawhin, J. An Extension of a Theorem of A. C. Lazer on Forced Nonlinear Oscillations J. Math. Anal. Appl. 40 1972 20-29 MR0313587

18 Mawhin, J.; Ward, J. R. Periodic Solutions of Some Forced Liénard Differential Equations at Resonance Arch. Math. 41 1983 337-351 MR0731606

19 Mazzi, L.; Sabatini, M. A Characterization of Centres via First Integrals J. Differential Equation 76 1988 222-237 MR0969422

20 Morris, G. R. A Case of Boundedness of Littlewood's Problem on Oscillatory Differential Equations Bull. Austral. Math. Soc. 14 1976 71-93 MR0402198

21 Omari, P.; Villari, Gab.; Zanolin, F. Periodic Solutions of the Liénard Equation with One-sided Growth Restrictions J. Differential Equations 67 1987 278-293 MR0879698

22 Opial, Z. Sur un Theoreme de A. Filippov Ann. Polon. Math. 5 1958 67-75 MR0097584

23 Rebelo, C.; Zanolin, F. Multiplicity Results for Periodic Solutions of Second Order ODEs with Asymmetric Nonlinearities Trans. Amer. Math. Soc. 348 1996 2349-2389 MR1344211

24 Struwe, M. Multiple Solutions of Anticoercive Boundary Value Problems for a Class of Ordinary Differential Equations of Second Order J. Differential Equation 37 1980 285-295 MR0587226

25 Sugie, J.; Hara, T. Classification of Global Phase Portraits of a System of Liénard Type J. Math. Anal. Appl. 193 1995 264-281 MR1338512

26 Sugie, J.; Hara, T. Non-existence of Periodic Solutions of the Liénard System J. Math. Anal. Appl. 159 1991 224-236 MR1119432

27 Sugie, J.; Yoneyama, T. On the Liénard System Which Has No Periodic Solutions Math. Proc. Camb. Phil. Soc. 113 1993 413-422 MR1198422

28 Villari, Gab.; Zanolin, F. On Forced Nonlinear Oscillations of a Second Order Equation with Strong Restoring Term Funkcial. Ekvac. 31 1988 383-395 MR0987793 0987793 29 Villari, Gab.; Zanolin, F. On a Dynamical System in the Liénard Plane. Necessary and Sufficient Conditions for the Intersection with the Vertical Isocline And Applications Funkcial. Ekvac. 33 1990 19-38 MR1065466 1065466 30 Villari, Gab.; Zanolin, F., A Continuation Theorem with Applications to Periodically Forced Liénard Equations in Presence of a Separatrix, Ann. Mat. Pura Appl., to appear MR1877624