@book { Undwerksstmich,
    title = "Und wer küsst mich?",
    author = "Heide {John}",
    year = "2012",
    publisher = "hey! publishing",
    address = "München, Deutschland",
    doi = "10.3239/9783942822176",
    url = "https://www.heypublishing.com/document/206222"
}