@book { DieFlirtschule,
    title = "Die Flirtschule",
    author = "Christina {Zacker}",
    year = "2013",
    publisher = "dotbooks Verlag",
    address = "München, Deutschland",
    doi = "10.3239/9783955201258",
    url = "https://m.dotbooks.de/document/208162"
}