@book { DerPrfingenieurfrBauleistungen,
    title = "Der Prüfingenieur für Bauleistungen",
    author = "Frank {Kluth}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1098401"
}