@book { MakeorBuyVorundNachteile,
    title = "Make or Buy: Vor- und Nachteile",
    author = "Markus {Zabel} and Maximilian {Lerch} and Lukas {Scharnberg}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640823642",
    url = "https://www.hausarbeiten.de/document/166310"
}