Monotone iterative techniques for discontinuous nonlinear differential equations S Heikkila, V Lakshmikantham CRC Press, 1994 | 756 | 1994 |

Fixed point theory in ordered sets and applications: from differential and integral equations to game theory S Carl, S Heikkilä Springer Science & Business Media, 2010 | 194 | 2010 |

Nonlinear differential equations in ordered spaces S Carl, S Heikkila Chapman and Hall/CRC, 2000 | 179 | 2000 |

On fixed points of multifunctions in ordered spaces S Heikkilä Applicable Analysis 51 (1-4), 115-127, 1993 | 43 | 1993 |

Fixed point theorems and their applications to theory of Nash equilibria S Heikkilä, K Reffett Nonlinear Analysis: Theory, Methods & Applications 64 (7), 1415-1436, 2006 | 39 | 2006 |

Elliptic problems with lack of compactness via a new fixed point theorem S Carl, S Heikkilä Journal of Differential Equations 186 (1), 122-140, 2002 | 37 | 2002 |

On fixed points through a generalized iteration method with applications to differential and integral equations involving discontinuities. S Heikkilä NONLINEAR ANAL. THEORY METHODS APPLIC. 14 (5), 413-426, 1990 | 35 | 1990 |

On extremal solutions of an elliptic boundary value problem involving discontinuous nonlinearities S Carl, S Heikkilä | 33 | 1992 |

On first order discontinuous differential equations with nonlinear boundary conditions S Heikkila, A Cabada Nonlinear World 3, 487-504, 1996 | 32 | 1996 |

On a parabolic boundary value problem with discontinuous nonlinearity S Carl, S Heikkilä Nonlinear Analysis: Theory, Methods & Applications 15 (11), 1091-1095, 1990 | 31 | 1990 |

A unified theory for first-order discontinuous scalar differential equations S Heikkilä, V Lakshmikantham Nonlinear Analysis: Theory, Methods & Applications 26 (4), 785-797, 1996 | 29 | 1996 |

Applications of monotone techniques to differential equations with discontinuous right-hand side S Heikkilä, V Lakshmikantham, S Leela | 26 | 1988 |

Elliptic equations with discontinuous nonlinearities in RN S Carl, S Heikkilä Nonlinear Analysis: Theory, Methods & Applications 31 (1-2), 217-227, 1998 | 24 | 1998 |

An existence result for elliptic differential inclusions with discontinuous nonlinearity S Carl, S Heikkilä Nonlinear Analysis: Theory, Methods & Applications 18 (5), 471-479, 1992 | 24 | 1992 |

A method to solve discontinuous boundary value problems S Heikkilä Nonlinear Analysis: Theory, Methods & Applications 47 (4), 2387-2394, 2001 | 23 | 2001 |

On discontinuous implicit evolution equations S Carl, S Heikkilä Journal of mathematical analysis and applications 219 (2), 455-471, 1998 | 22 | 1998 |

On solvability of first order discontinuous scalar differential equations S Carl, S Heikkilä, M Kumpulainen Nonlinear Times Digest 2 (1), 11-27, 1995 | 22 | 1995 |

Convergence theorems for HL integrable vector-valued functions with applications S Heikkilä, M Kumpulainen, S Seikkala Nonlinear Analysis: Theory, Methods & Applications 70 (5), 1939-1955, 2009 | 21 | 2009 |

Uniqueness and existence results for ordinary differential equations JA Cid, S Heikkilä, RL Pouso Journal of mathematical analysis and applications 316 (1), 178-188, 2006 | 21 | 2006 |

Extremality and comparison results for discontinuous third order functional initial-boundary value problems A Cabada, S Heikkilä Journal of mathematical analysis and applications 255 (1), 195-212, 2001 | 21 | 2001 |