@book { DieRollentheorieaussozialpsychologischerSicht,
    title = "Die Rollentheorie aus sozialpsychologischer Sicht",
    author = "Ellen {Ziegler}",
    year = "2008",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638065566",
    url = "https://www.hausarbeiten.de/document/92592"
}