@book { PsychologischeDiagnostikmentalerFitnessimSport,
    title = "Psychologische Diagnostik mentaler Fitness im Sport",
    author = "Alexandre {Gerwinat}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1108031"
}