@book { AusdauertrainingGestaltungeinesTrainingsplans,
    title = "Ausdauertraining. Gestaltung eines Trainingsplans",
    author = "Simon {Kallenberger}",
    year = "2015",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    url = "https://www.hausarbeiten.de/document/313150"
}