@techreport{HKOW10,
  title = "Reachability in Parametric One-Counter Automata",
  author = "Christoph Haase and Stephan Kreutzer and Joel Ouaknine and James Worrell",
  year = "2010",
  note = "Unpublished draft.",
  url = "http://www.comlab.ox.ac.uk/files/2833/iandc.pdf",
}