@book { HeinrichHaashattenur30TagedasFlugmaschinenfhrerZeugnisNr24,
    title = "„Heinrich Haas hatte nur 30 Tage das Flugmaschinenführer-Zeugnis Nr. 24“",
    author = "Alexander {Kauther} and Paul {Wirtz}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640987405",
    url = "https://www.hausarbeiten.de/document/176928"
}