@book { DieRelativittdesGewerkschaftsbegriffs,
    title = "Die Relativität des Gewerkschaftsbegriffs",
    author = "Burkhard {Wahl}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1071839"
}