@book { IntroductiontoPolishTaxLaw,
    title = "Introduction to Polish Tax Law",
    author = "Paweł {Smoleń} and Marcin {Burzec}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b14482",
    url = "https://www.peterlang.com/document/1062504"
}