@TechReport{ Purver02CRMarkup,
  author = "Purver, Matthew",
  title = "A Clarification Request Markup Scheme for the {BNC}",
  institution = "Department of Computer Science, King's College London",
  number = "TR-02-02",
  url = "ftp://ftp.dcs.kcl.ac.uk/pub/tech-reports/tr02-02.ps.gz",
  year = 2002,
  month = feb,
  url = "http://www.dcs.qmul.ac.uk/~mpurver/papers/purver02crmarkup.pdf",
}