@unpublished{Hun11,
  title = "{LIFO-search on digraphs: A searching game for cycle-rank}",
  author = "Paul Hunter",
  year = "2011",
  note = "To be presented at the 18th International Symposium on Fundamentals of Computation Theory (FCT 2011)",
  url = "http://www.comlab.ox.ac.uk/people/Paul.Hunter/papers/lifo-digraph.pdf",
}