@CONFERENCE{fabioc2004007,
	author = "S. Wu and F. Crestani",
	title = "Shadow Document Methods of Results Merging",
	booktitle = "Proceedings of ACM SAC 2004",
	year = "2004",
	pages = "1067-1072",
	address = "Nicosia, Cyprus",
	month = "March",
}