@book { NachhaltigerBergtourismus,
    title = "Nachhaltiger Bergtourismus",
    author = "Stefanie {Wachter}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832466688",
    url = "https://m.diplom.de/document/222049"
}