@book { StdtetourismusinFreiburg,
    title = "Städtetourismus in Freiburg",
    author = "Matthias {Fuchs}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832491871",
    url = "https://m.diplom.de/document/224312"
}