@book { PsychologischeAspektederKundenorientierung,
    title = "Psychologische Aspekte der Kundenorientierung",
    author = "Christian {Schnippe}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1090139"
}