@incollection{
    Niemela93:tae,
    editor = {Hyv\"onen, E. and Karanta, I. and Syrj\"anen, M.},
    author = {Niemel{\"a}, Ilkka},
    chapter = "",
    publisher = "Gaudeamus",
    title = {Logiikka tiet\"amyskielen\"a},
    booktitle = {Teko\"alyn ensyklopedia},
    address = "",
    month = "",
    year = "1993",
    pages = "116--124"
}