@book { KurtLewinPersonWerkUmfeld,
    title = "Kurt Lewin – Person, Werk, Umfeld",
    author = "Wolfgang {Schönpflug} and Wolfgang {Schönpflug}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1102720"
}