@book { Hochschulkostenrechnung,
    title = "Hochschulkostenrechnung",
    author = "Martin {Hartmann}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832448738",
    url = "https://m.diplom.de/document/220442"
}