@book { DerDoppelaspektdesGeistes,
    title = "Der Doppelaspekt des Geistes",
    author = "Gerhard {Loettel}",
    year = "2012",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-00529-5",
    url = "https://www.peterlang.com/document/1054177"
}