@book { Designingofprestressedconcretewithaninternetbasedsoftware,
    title = "Designing of pre-stressed concrete with an internet based software",
    author = "Michael {Kollinger}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832456719",
    url = "https://m.diplom.de/document/221150"
}