@book { RubensPeterPaul,
    title = "Rubens, Peter Paul",
    author = "Fabian {Friebel}",
    year = "2001",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638995412",
    url = "https://www.hausarbeiten.de/document/101120"
}