@inproceedings{SIGMOD-2008-BansalGK,
	author        = "Nilesh Bansal and Sudipto Guha and Nick Koudas",
	booktitle     = "{Proceedings of the 26th ACM SIGMOD International Conference on Management of Data}",
	doi           = "10.1145/1376616.1376626",
	isbn          = "978-1-60558-102-6",
	pages         = "67--78",
	publisher     = "{ACM}",
	title         = "{Ad-hoc aggregations of ranked lists in the presence of hierarchies}",
	year          = 2008,
}