@techreport{Nupponen05Design,
  author = "Nupponen, Kimmo",
  title = "{The design and implementation of a graph rewrite engine for model transformations}",
  institution = "Department of Computer Science and Engineering, Helsinki University of Technology",
  month = "May",
  year = "2005",
  url = "http://www.niksula.hut.fi/~knuppone/thesis.pdf",
}