@book { Massenpsychologie,
    title = "Massenpsychologie",
    author = "Mischa {Kölle}",
    year = "2010",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640614622",
    url = "https://www.hausarbeiten.de/document/149103"
}