@techreport{
    Niemela86,
    author = {Niemel{\"a}, Ilkka},
    title = "A Survey of Nonmonotonic Logic (in {Finnish})",
    address = "Espoo",
    number = "A22",
    month = "",
    year = "1986",
    type = "Internal report",
    institution = "Helsinki University of Technology, Digital Systems Laboratory"
}