@book { WalterHasencleversHumanitarianism,
    title = "Walter Hasenclever's Humanitarianism",
    subtitle = "Themes of Protest in His Works",
    author = "Alfred {Hoelzel}",
    year = "1983",
    publisher = "Peter Lang Verlag",
    address = "New York, United States of America",
    url = "https://www.peterlang.com/document/1073453"
}