@book { Collapseanalysisofexternallyprestressedstructures,
    title = "Collapse analysis of externally prestressed structures",
    author = "Jens {Tandler}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/226205"
}