@book { PremiumPricePromotion,
    title = "Premium Price-Promotion",
    author = "Felix {Zöllner}",
    year = "2015",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-05220-6",
    url = "https://www.peterlang.com/document/1049270"
}