@book { ErfolgdurchintegrativeskoMarketing,
    title = "Erfolg durch integratives Öko-Marketing",
    author = "Georg {Lehle}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832459000",
    url = "https://m.diplom.de/document/221354"
}