Marek **Balcerzak**, Lodz University of Technology |

Artur **Bartoszewicz**, Łódź University |

Judyta **Bąk**, Jan Kochanowski University |

Zoltán **Boros**, University of Debrecen, Debrecen, Hungary |

Martin **Doležal**, Institute of Mathematics, Czech Academy of Sciences |

Peter **Eliaš**, Mathematical Institute, Slovak Academy of Sciences, Košice, Slovakia |

Małgorzata **Filipczak**, Lodz University, Lodz, Poland |

Ľubica **Holá**, Mathematical Institute, Slovak Academy of Sciences, Bratislava, Slovakia |

Dušan **Holý**, Faculty of Education, Trnava University, Trnava |

Grażyna **Horbaczewska**, University of Lodz |

Eliza **Jabłońska**, AGH University of Science and Technology, Faculty of Applied Mathematics |

Jacek **Jachymski**, Lodz University of Technology |

Stanisław **Kowalczyk**, Pomeranian University in Słupsk |

Ondřej **Kurka**, Institute of Mathematics, Czech Academy of Sciences |

Sebastian **Lindner**, University of Łódź, Poland |

Jesús **Llorente**, Universidad Complutense de Madrid, Madrid, Spain |

Adam **Marton**, Institute of Mathematics, Pavol Jozef Šafárik University in Košice, Slovakia |

Milan **Matejdes**, Trnava University in Trnava |

Branislav **Novotný**, Mathematical Institute, Slovak Academy of Sciences, Bratislava, Slovakia |

Piotr **Nowakowski**, University of Lodz, Faculty of Mathematics and Computer Science, Lodz, Poland |

Martin **Papčo**, Catholic University in Ruzomberok; Mathematical Institute, Slovak Academy of Sciences, Slovakia |

Emilia **Przemska**, Pomeranian University in Słupsk |

Jaroslav **Šupina**, UPJŠ Košice |

Małgorzata **Terepeta**, Lodz University of Technology |

Péter **Tóth**, University of Debrecen, Debrecen, Hungary |

Małgorzata **Turowska**, Pomeranian University in Słupsk |

Artur **Wachowicz**, Institute of Mathematics, Lodz University of Technology, Poland |

Renata **Wiertelak**, University of Lodz, Poland |