@book { DarstellungderkapitalmarkttheoretischenEffizienzsteigerungdesEigenportfoliosDepotA,
    title = "Darstellung der kapitalmarkttheoretischen Effizienzsteigerung des Eigenportfolios (Depot A)",
    author = "Michael {Winker}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832447281",
    url = "https://m.diplom.de/document/220329"
}