@book { NokiaCaseStudyHowcanNokiamaintainitsmarketpositioninthematureEuropeanmarket,
    title = "Nokia Case Study: How can Nokia maintain its market position in the mature European market?",
    author = "",
    year = "2006",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638479714",
    url = "https://www.hausarbeiten.de/document/52193"
}