@book { UntersuchungenzurexternenVorspannunganHohlkastenbrcken,
    title = "Untersuchungen zur externen Vorspannung an Hohlkastenbrücken",
    author = "Jens {Tandler}",
    year = "1999",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832416409",
    url = "https://m.diplom.de/document/217518"
}