@InProceedings{doem,
  author = 	 {S. S. Chawathe and S. Abiteboul and J. Widom},
  title = 	 {Representing and Querying Changes in Semistructured Data},
  booktitle = 	 {Proceedings of the International Conference on Data
                  Engineering}, 
  month =	 feb,
  year =	 1998
}