@book { KeepingtheSourcesPure,
    title = "«Keeping the Sources Pure»",
    subtitle = "The Making of George Mackay Brown",
    author = "Sabine {Schmid}",
    year = "2003",
    publisher = "Peter Lang Verlag",
    address = "Oxford, United Kingdom",
    url = "https://www.peterlang.com/document/1094832"
}