@incollection{
    HN2000:lncs,
    editor = {Husberg, Nisse and Janhunen, Tomi and Niemel\"a, Ilkka},
    author = {Heljanko, Keijo and Niemel{\"a}, Ilkka},
    chapter = "",
    publisher = "Helsinki University of Technology, Laboratory for Theoretical Computer Science",
    title = "Petri Net Analysis and Nonmonotonic Reasoning",
    booktitle = "Leksa Notes in Computer Science, Festschrift in Honour of Professor {Leo Ojala}",
    address = "",
    month = "",
    note = "",
    year = "2000",
    pages = "7--19"
}