@book { LoyaltyProfiling,
    title = "«Loyalty Profiling»",
    author = "Martin {Lafleur}",
    year = "2011",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-00344-4",
    url = "https://www.peterlang.com/document/1044196"
}