@book { GUTBSEeinJanuskopf,
    title = "GUT / BÖSE – ein Januskopf?",
    author = "Eva {Marsal} and Regina {Speck}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1105566"
}