@book { MarktundMotivation,
    title = "Markt und Motivation",
    subtitle = "Wie ökonomische Anreize die (Arbeits-)Moral verdrängen",
    author = "Bruno S. {Frey}",
    year = "2015",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1220963"
}