@book { MarktanalyseundMarketingplanungfreinDamenfitnessstudioinHannover,
    title = "Marktanalyse und Marketingplanung für ein Damenfitnessstudio in Hannover",
    author = "Lisa {Sommer}",
    year = "2019",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    url = "https://www.hausarbeiten.de/document/492403"
}