@book { kologieorientierteProfilierungimvertikalenMarketing,
    title = "Ökologieorientierte Profilierung im vertikalen Marketing",
    author = "Michael {Ceyp} and  {Universität Münster}",
    year = "1997",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b13630",
    url = "https://www.peterlang.com/document/1068226"
}