Connection between black-hole quasinormal modes and lensing in the strong deflection limit IZ Stefanov, SS Yazadjiev, GG Gyulchev Physical review letters 104 (25), 251103, 2010 | 161 | 2010 |

Gravitational lensing by rotating naked singularities GN Gyulchev, SS Yazadjiev Physical Review D 78 (8), 083004, 2008 | 111 | 2008 |

Kerr-Sen dilaton-axion black hole lensing in the strong deflection limit GN Gyulchev, SS Yazadjiev Physical Review D 75 (2), 023006, 2007 | 108 | 2007 |

On the shadow of rotating traversable wormholes G Gyulchev, P Nedkova, V Tinchev, S Yazadjiev The European Physical Journal C 78, 1-12, 2018 | 106 | 2018 |

Weak Gravitational lensing by phantom black holes and phantom wormholes using the Gauss–Bonnet theorem A Övgün, G Gyulchev, K Jusufi Annals of Physics 406, 152-172, 2019 | 105 | 2019 |

Image of the Janis-Newman-Winicour naked singularity with a thin accretion disk G Gyulchev, P Nedkova, T Vetsov, S Yazadjiev Physical Review D 100 (2), 024055, 2019 | 90 | 2019 |

Gravitational lensing by phantom black holes GN Gyulchev, IZ Stefanov Physical Review D 87 (6), 063005, 2013 | 61 | 2013 |

Distinguishing rotating naked singularities from Kerr-like wormholes by their deflection angles of massive particles K Jusufi, A Banerjee, G Gyulchev, M Amir The European Physical Journal C 79, 1-13, 2019 | 45 | 2019 |

Observational signatures of strongly naked singularities: image of the thin accretion disk G Gyulchev, J Kunz, P Nedkova, T Vetsov, S Yazadjiev The European Physical Journal C 80, 1-20, 2020 | 44 | 2020 |

Image of the thin accretion disk around compact objects in the Einstein–Gauss–Bonnet gravity G Gyulchev, P Nedkova, T Vetsov, S Yazadjiev The European Physical Journal C 81, 1-10, 2021 | 37 | 2021 |

Photon surfaces, shadows, and accretion disks in gravity with minimally coupled scalar field I Bogush, D Gal’tsov, G Gyulchev, K Kobialko, P Nedkova, T Vetsov Physical Review D 106 (2), 024034, 2022 | 18 | 2022 |

Shadows of black holes in vector-tensor galileons modified gravity T Vetsov, G Gyulchev, S Yazadjiev arXiv preprint arXiv:1801.04592, 2018 | 17 | 2018 |

Analytical Kerr-Sen dilaton-axion black hole lensing in the weak deflection limit GN Gyulchev, SS Yazadjiev Physical Review D 81 (2), 023005, 2010 | 13 | 2010 |

Cusp structure in shadows casted by rotating wormholes G Gyulchev, P Nedkova, V Tinchev, S Yazadjiev AIP Conference Proceedings 2075 (1), 2019 | 11 | 2019 |

Polarized image of equatorial emission in horizonless spacetimes: Traversable wormholes V Deliyski, G Gyulchev, P Nedkova, S Yazadjiev Physical Review D 106 (10), 104024, 2022 | 9 | 2022 |

Gravitational lensing by rotating naked singularities in the equatorial plane G Gyulchev, S Yazadjiev AIP Conference Proceedings 946 (1), 106-118, 2007 | 8 | 2007 |

Yazadjiev, S2018EPJC. 78. 544G. vol. 78 G Gyulchev, P Nedkova, V Tinchev Eur. Phys. J. C, 544, 2018 | 7 | 2018 |

Quasiperiodic oscillations and Tomimatsu-Sato δ= 2 space-time IZ Stefanov, GG Gyulchev, SS Yazadjiev Physical Review D 87 (8), 083005, 2013 | 6 | 2013 |

78h3004G. vol. 78 GN Gyulchev, S Yazadjiev Phys. Rev. D, 083004, 2008 | 5 | 2008 |

Polarized image of equatorial emission in horizonless spacetimes: Naked singularities V Deliyski, G Gyulchev, P Nedkova, S Yazadjiev Physical Review D 108 (10), 104049, 2023 | 3 | 2023 |