@book { SicherheitundDatenschutzimInternet,
    title = "Sicherheit und Datenschutz im Internet",
    author = "Patrick {Hammer}",
    year = "2001",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638101462",
    url = "https://www.hausarbeiten.de/document/195"
}