@book { NutzungvonBiogasinBrennstoffzellen,
    title = "Nutzung von Biogas in Brennstoffzellen",
    author = "Jan {Adolph}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/218807"
}