@phdthesis{
    Heljanko2002,
    author = "Heljanko, Keijo",
    school = "Helsinki University of Technology, Laboratory for Theoretical Computer Science, Research Reports 71",
    title = "Combining Symbolic and Partial Order Methods for Model Checking 1-Safe Petri Nets",
    url = "http://lib.tkk.fi/Diss/2002/isbn9512258935/",
    address = "Espoo, Finland",
    flags = "",
    year = "2002",
    owner = "MM",
    impactfactor = "G5"
}