@book { DerGutenbergBuchdruck,
    title = "Der Gutenberg Buchdruck",
    author = "Thomas {Hallmann}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656080831",
    url = "https://www.hausarbeiten.de/document/183701"
}