@book { EinMittlerundvieleVermittlungen,
    title = "Ein Mittler und viele Vermittlungen",
    author = "Krystian {Kaluza}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1108217"
}