@book { ProjektentwicklungimObjektbereichBrobauten,
    title = "Projektentwicklung im Objektbereich Bürobauten",
    author = "Markus {Keßler}",
    year = "1999",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832415570",
    url = "https://m.diplom.de/document/217399"
}