@book { UntersuchungenzurFrosteindringungindenStraenaufbau,
    title = "Untersuchungen zur Frosteindringung in den Straßenaufbau",
    author = "Markus {Spiegl}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832456382",
    url = "https://m.diplom.de/document/221118"
}