@book { QualittsbeurteilunginvestiverDienstleistungen,
    title = "Qualitätsbeurteilung investiver Dienstleistungen",
    author = "Bernd {Büker} and  {Universität Münster}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b13635",
    url = "https://www.peterlang.com/document/1068230"
}