@book { CooperativeSourcing,
    title = "Cooperative Sourcing",
    subtitle = "Erklärung und Gestaltung horizontaler Beschaffungskooperationen in der Industrie",
    author = "Michael {Essig}",
    year = "1999",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1088287"
}