@book { SymbolonBand21,
    title = "Symbolon - Band 21",
    subtitle = "Himmelsreisen und Höllenfahrten. Klang und Kosmos. Zeit und Zeitlosigkeit",
    author = "Werner {Heinz}",
    year = "2020",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b16739",
    url = "https://www.peterlang.com/document/1111411"
}