@book { ModellbildunginderMassenpsychologie,
    title = "Modellbildung in der Massenpsychologie",
    author = "Thomas {Fenzl}",
    year = "2007",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638894463",
    url = "https://www.hausarbeiten.de/document/84504"
}