@book { ThePoliticalSystemofPoland,
    title = "The Political System of Poland",
    author = "Stanisław {Sulowski} and Tomasz {Słomka}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b19264",
    url = "https://www.peterlang.com/document/1161814"
}