@book { VattenfallsentryintothePolishmarket,
    title = "Vattenfall’s entry into the Polish market",
    author = "Dennis {Eggert} and Sarah {Bentolila} and Caroline {Dumont}",
    year = "2007",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638801409",
    url = "https://www.hausarbeiten.de/document/76536"
}