@book { HomosexualittimprofessionellenMnnerfuballEinkulturellerWandel,
    title = "Homosexualität im professionellen Männerfußball: Ein kultureller Wandel?",
    author = "Lukas {Niggel}",
    year = "2015",
    publisher = "BACHELOR + MASTER PUBLISHING",
    address = "Hamburg, Deutschland",
    url = "https://m.bachelor-master-publishing.de/document/297576"
}