@book { StreetworkinderDrogenszene,
    title = "Streetwork in der Drogenszene",
    author = "Franziska {Marr}",
    year = "2007",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638628853",
    url = "https://www.hausarbeiten.de/document/70044"
}