@book { VertragsmanagementfrInvestitionsprojekte,
    title = "Vertragsmanagement für Investitionsprojekte",
    author = "Bernd {Slaghuis}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b14027",
    url = "https://www.peterlang.com/document/1068563"
}