@book { IntrinsischeversusextrinsischeMotivation,
    title = "Intrinsische versus extrinsische Motivation",
    author = "Sandra {Peters}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640865864",
    url = "https://www.hausarbeiten.de/document/168783"
}