@book { MigrationinEuropa,
    title = "Migration in Europa",
    author = "Alexander {Stadlmayr}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656053545",
    url = "https://www.hausarbeiten.de/document/180642"
}