@book { NeuesLichtaufEllenKey,
    title = "Neues Licht auf Ellen Key",
    author = "Margrit {Hansen}",
    year = "2017",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b11074",
    url = "https://www.peterlang.com/document/1110096"
}