@book { StefiGeyer,
    title = "Stefi Geyer",
    author = "Helga {Varadi} and Dominik {Sackmann}",
    year = "2020",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    doi = "10.3726/b17006",
    url = "https://www.peterlang.com/document/1059116"
}