@book { DerGmbHGeschftsfhreralsVerbraucher,
    title = "Der GmbH-Geschäftsführer als Verbraucher",
    author = "Hannes {Thormann}",
    year = "2019",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b10463",
    url = "https://www.peterlang.com/document/1050778"
}