@book { UmweltmanagementinderEnergieundWasserversorgung,
    title = "Umweltmanagement in der Energie- und Wasserversorgung",
    subtitle = "Am Beispiel der Stadtwerke Karlsruhe",
    author = "Isabelle {Nester}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832437602",
    url = "https://m.diplom.de/document/219443"
}