@book { ArbeitsbuchChristopherEcker,
    title = "Arbeitsbuch Christopher Ecker",
    subtitle = "Aufsätze und Materialien",
    author = "Kai U. {Jürgens}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b19000",
    url = "https://www.peterlang.com/document/1159134"
}