@book { EstimatingbetaandCostofEquityCapitalforNontradedTransportationCompanies,
    title = "Estimating beta and Cost of Equity Capital for Non-traded Transportation Companies",
    author = "Sascha {Heller}",
    year = "2011",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/228442"
}