@book { MotiveundMotivationinderTrendsportartBeachvolleyball,
    title = "Motive und Motivation in der Trendsportart Beachvolleyball",
    author = "Judith {Meyer}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836619851",
    url = "https://m.diplom.de/document/226180"
}