@book { ImHerzenderBergwelt,
    title = "Im Herzen der Bergwelt",
    author = "Alfred {Bekker} and Anna {Martach}",
    year = "2019",
    publisher = "Uksak E-Books",
    address = "Lengerich, Deutschland",
    url = "https://uksakebooks.grin.com/document/306683"
}