@book { GrauerKapitalmarkt,
    title = "«Grauer Kapitalmarkt»",
    author = "Sigmund P. {Martin} and Nina {Scherer} and Diana {Hube} and Guntram {Scheer}",
    year = "2015",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-06409-4",
    url = "https://www.peterlang.com/document/1050038"
}