@book { EineFitnesseinheitVertrauen,
    title = "Eine Fitnesseinheit Vertrauen",
    author = "Ulla B. {Müller}",
    year = "2022",
    publisher = "via tolino media",
    address = "München, Deutschland",
    url = "https://tolino.openpublishing.com/document/1282776"
}