@book { DasDritteEnergiepaketfrdenGasbereich,
    title = "Das Dritte Energiepaket für den Gasbereich",
    author = "Franz Jürgen {Säcker}",
    year = "2010",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-00253-9",
    url = "https://www.peterlang.com/document/1054308"
}