@book { CredoeinesHumanisten,
    title = "Credo eines Humanisten",
    subtitle = "Some Beliefs of Man, in Man, for Man",
    author = "Erich {Fromm} and Rainer {Funk}",
    year = "2015",
    publisher = "Edition Erich Fromm",
    address = "München, Deutschland",
    url = "https://books.openpublishing.com/document/307255"
}