@book { PushundPullinderMarkenpolitik,
    title = "Push und Pull in der Markenpolitik",
    author = "Michael {Szeliga}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b13634",
    url = "https://www.peterlang.com/document/1068231"
}