@book { Weltwirtschaftskrise1929,
    title = "Weltwirtschaftskrise 1929",
    author = "Manuela {Metzger}",
    year = "2004",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640068296",
    url = "https://www.hausarbeiten.de/document/108634"
}