Subharmonic solutions for some second-order differential equations with singularities A Fonda, R Manásevich, F Zanolin SIAM Journal on Mathematical Analysis 24 (5), 1294-1311, 1993 | 146 | 1993 |

Uniformly persistent semidynamical systems A Fonda Proceedings of the American Mathematical Society, 111-116, 1988 | 105 | 1988 |

Nonlinear resonance in asymmetric oscillators C Fabry, A Fonda journal of differential equations 147 (1), 58-78, 1998 | 89 | 1998 |

Periodic solutions of nonlinear differential equations with double resonance C Fabry, A Fonda Annali di Matematica Pura ed Applicata 157 (1), 99-116, 1990 | 58 | 1990 |

Periodic solutions of asymptotically positively homogeneous differential equations A Fonda, P Habets Journal of Differential Equations 81 (1), 68-97, 1989 | 56 | 1989 |

Periodic oscillations for a nonlinear suspension bridge model A Fonda, Z Schneider, F Zanolin Journal of computational and applied mathematics 52 (1-3), 113-140, 1994 | 55 | 1994 |

Subharmonic solutions of conservative systems with nonconvex potentials A Fonda, AC Lazer Proceedings of the American Mathematical Society 115 (1), 183-190, 1992 | 53 | 1992 |

Quadratic forms, weighted eigenfunctions and boundary value problems for non-linear second order ordinary differential equations A Fonda, J Mawhin Proceedings of the Royal Society of Edinburgh Section A: Mathematics 112 (1 …, 1989 | 53 | 1989 |

Guiding functions and periodic solutions to functional-differential equations A Fonda Proceedings of the American Mathematical Society 99 (1), 79-85, 1987 | 53 | 1987 |

Periodic orbits of radially symmetric Keplerian-like systems: a topological degree approach A Fonda, R Toader Journal of Differential Equations 244 (12), 3235-3264, 2008 | 52 | 2008 |

Iterative and variational methods for the solvability of some semilinear equations in Hilbert spaces A Fonda, J Mawhin Journal of differential equations 98 (2), 355-375, 1992 | 52 | 1992 |

Periodic solutions of perturbed Hamiltonian systems in the plane by the use of the Poincaré-Birkhoff theorem A Fonda, M Sabatini, F Zanolin Topological Methods in Nonlinear Analysis 40 (1), 29-52, 2012 | 50 | 2012 |

Positively homogeneous Hamiltonian systems in the plane A Fonda Journal of Differential Equations 200 (1), 162-184, 2004 | 50 | 2004 |

Large-amplitude subharmonic oscillations for scalar second-order differential equations with asymmetric nonlinearities A Fonda, M Ramos Journal of differential equations 109 (2), 354-372, 1994 | 48 | 1994 |

On the use of time-maps for the solvability of nonlinear boundary value problems A Fonda, F Zanolin Archiv der Mathematik 59 (3), 245-259, 1992 | 45 | 1992 |

Subharmonic oscillations of forced pendulum-type equations A Fonda, M Willem Journal of Differential Equations 81 (2), 215-220, 1989 | 44 | 1989 |

A higher dimensional Poincaré–Birkhoff theorem for Hamiltonian flows A Fonda, AJ Ureña Annales de l'Institut Henri Poincaré C, Analyse non linéaire 34 (3), 679-698, 2017 | 39 | 2017 |

Planar differential systems at resonance A Fonda, J Mawhin Advances in Differential Equations 11 (10), 1111-1133, 2006 | 37 | 2006 |

Periodic solutions of scalar second order differential equations with a singularity A Fonda | 37 | 1993 |

Subharmonic solutions for second order differential equations A Fonda, M Ramos, M Willem Topological Methods in Nonlinear Analysis 1 (1), 49-66, 1993 | 34 | 1993 |