@book { NeueEnergietrgerimLuftverkehr,
    title = "Neue Energieträger im Luftverkehr",
    author = "Kagan {Eksik}",
    year = "2009",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640403134",
    url = "https://www.hausarbeiten.de/document/133638"
}