@InProceedings{xdiff,
  author = 	 {Sudarshan S. Chawathe},
  title = 	 {Comparing Hierarchical Data in External Memory},
  booktitle =    VLDB,
  annote = 	 {Proceedings of the Twenty-fifth International
                  Conference on Very Large Data Bases},
  year =	 1999,
  address =	 {Edinburgh, Scotland},
  month =	 sep,
  pages =	 {90--101}
}