@book { AComparativeHistoryofNationalOilCompanies,
    title = "A Comparative History of National Oil Companies",
    author = "Alain {Beltran}",
    year = "2011",
    publisher = "Peter Lang Verlag",
    address = "Bruxelles, Belgium",
    doi = "10.3726/978-3-0352-6001-4",
    url = "https://www.peterlang.com/document/1043999"
}