@phdthesis{
    ukkonen08thesis,
    author = "Ukkonen, Antti",
    school = "Helsinki University of Technology",
    optmonth = "",
    title = "Algorithms for Finding Orders and Analyzing Sets of Chains",
    optnote = "",
    year = "2008",
    opttype = "",
    optannote = "",
    optkey = "",
    optaddress = ""
}