@book { Das5MinutenTrampolinTraining,
    title = "Das 5-Minuten-Trampolin-Training",
    author = "Manuel {Eckardt}",
    year = "2017",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403130"
}