@INPROCEEDINGS {
	AUTHOR = "Pablo Barcel{\'o} and Leonid Libkin and Antonella Poggi and Cristina Sirangelo",
	TITLE = "XML with Incomplete Information: Models, Properties and Query Answering",
	EDITOR = "Jan Paredaens and Jianwen Su",
	BOOKTITLE = "28th ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems (PODS)",
	PAGES = "237-246",
	MONTH = "Jun",
	YEAR = "2009",
	ADDRESS = "Providence, Rhode Island",
	PUBLISHER = "ACM Press",
	SERIES ="ACM International Conference Proceeding Series",
	ISBN = "978-1-60558-553-6",
	}