@book { MarketingimliberalisiertenStrommarkt,
    title = "Marketing im liberalisierten Strommarkt",
    author = "Thomas {Haller}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b13952",
    url = "https://www.peterlang.com/document/1068501"
}