@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}, year = 1998, month = feb, address = {Orlando, Florida}, pages = 4--13, note = {Available at http://www-db.stanford.edu} }