@book { BetriebswirtschaftlicheEffektevonOpenSourceSoftwareinKMU,
    title = "Betriebswirtschaftliche Effekte von Open Source Software in KMU",
    author = "Stephan {Hennig}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836620208",
    url = "https://m.diplom.de/document/226222"
}