@book { KundenzufriedenheitundKundenloyalitt,
    title = "Kundenzufriedenheit und Kundenloyalität",
    author = "Philipp {Siebrecht}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1098004"
}