Warning - the bibtex entry below may be invalid: 
Missing 'booktitle' 
@conference{IncSymmBreaking,
  author = "Karen Petrie with Chris Jefferson",
  journal = "In Proc. International Symmetry Conference",
  title = "Incremental Symmetry Breaking",
  url = "http://isc.cs.st-andrews.ac.uk/",
  year = "2007",
}