@book { MentalesTraininginderSnowboardausbildung,
    title = "Mentales Training in der Snowboardausbildung",
    author = "Oliver {Ecker}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836616782",
    url = "https://m.diplom.de/document/225999"
}