@book { TreuegebotTreuepflichtTreuebindung,
    title = "Treuegebot – Treuepflicht – Treuebindung",
    author = "Thomas {Zwissler}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1093975"
}