Differential equations with maxima DD Bainov, SG Hristova Crc Press, 2011 | 152 | 2011 |

Non-Instantaneous Impulses in Differential Equations R Agarwal, S Hristova, D O’Regan | 148 | 2017 |

A survey of Lyapunov functions, stability and impulsive Caputo fractional differential equations R Agarwal, S Hristova, D O’Regan Fractional Calculus and Applied Analysis 19 (2), 290-318, 2016 | 128 | 2016 |

Stability of Caputo fractional differential equations by Lyapunov functions R Agarwal, D O’Regan, S Hristova Applications of Mathematics 60, 653-676, 2015 | 108 | 2015 |

Monotone-iterative techniques of V. Lakshmikantham for a boundary value problem for systems of impulsive differential-difference equations SG Hristova, DD Bainov Journal of mathematical analysis and applications 197 (1), 1-13, 1996 | 67 | 1996 |

Stability by Lyapunov like functions of nonlinear differential equations with non-instantaneous impulses R Agarwal, D O’regan, S Hristova Journal of Applied Mathematics and Computing 53, 147-168, 2017 | 63 | 2017 |

Non-instantaneous impulses in Caputo fractional differential equations R Agarwal, S Hristova, D O’Regan Fractional Calculus and Applied Analysis 20 (3), 595-622, 2017 | 62 | 2017 |

Periodic boundary value problems for systems of first order impulsive differential equations DD Bainov, SG Hristova, S Hu, V Lakshmikantham Differential and Integral Equations 2 (1), 37-43, 1989 | 45 | 1989 |

Monotone iterative technique for the initial value problem for differential equations with non-instantaneous impulses R Agarwal, D O'Regan, S Hristova Applied Mathematics and Computation 298, 45-56, 2017 | 44 | 2017 |

Noninstantaneous impulses in Caputo fractional differential equations and practical stability via Lyapunov functions R Agarwal, S Hristova, D O’Regan Journal of the Franklin Institute 354 (7), 3097-3119, 2017 | 41 | 2017 |

Lyapunov functions and strict stability of Caputo fractional differential equations R Agarwal, S Hristova, D O’Regan Advances in Difference Equations 2015, 1-20, 2015 | 41 | 2015 |

Exponential stability for differential equations with random impulses at random times R Agarwal, S Hristova, D O’Regan Advances in Difference Equations 2013, 1-12, 2013 | 40 | 2013 |

Stability of nonlinear Volterra integro-differential equations with Caputo fractional derivative and bounded delays S Hristova, C Tunc Texas State University, Department of Mathematics, 2019 | 38 | 2019 |

Practical stability with respect to initial time difference for Caputo fractional differential equations R Agarwal, D O’Regan, S Hristova, M Cicek Communications in Nonlinear Science and Numerical Simulation 42, 106-120, 2017 | 38 | 2017 |

Stability of solutions to impulsive Caputo fractional differential equations RP Agarwal, S Hristova, D O'Regan Texas State University, Department of Mathematics, 2016 | 37* | 2016 |

Integral stability in terms of two measures for impulsive functional differential equations SG Hristova Mathematical and Computer Modelling 51 (1-2), 100-108, 2010 | 35 | 2010 |

Qualitative investigations and approximate methods for impulsive equations SG Hristova Nova Science Publishers, 2009 | 34 | 2009 |

Health care systems in transition: Bulgaria S Koulaksazov, S Todorova, E Tragakes, S Hristova, ... World Health Organization. Regional Office for Europe, 2003 | 32 | 2003 |

Stability on a cone in terms of two measures for impulsive differential equations with “supremum” SG Hristova Applied mathematics letters 23 (5), 508-511, 2010 | 31 | 2010 |

Existence of periodic solutions of nonlinear systems of differential equations with impulse effect SG Hristova, DD Bainov Journal of mathematical analysis and applications 125 (1), 192-202, 1987 | 31 | 1987 |