@book { UnderachieverHochbegabteProblemkinder,
    title = "Underachiever - Hochbegabte Problemkinder",
    author = "Andreas {Krenner}",
    year = "2014",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/273839"
}