@book { MessmethodenfrdieErfogskontrollevonsalesPromotion,
    title = "Messmethoden für die Erfogskontrolle von sales Promotion",
    author = "Nestor  T. {Kalala}",
    year = "2005",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640073726",
    url = "https://www.hausarbeiten.de/document/109190"
}