@article{dksd-is10,
	author={A. Deligiannakis and Y. Kotidis and V. Stoumpos and A. Delis},
	title={{Collection Trees for Event-Monitoring Queries}},
	journal={Information Systems},
	volume={36},
	number={2},
	month={April},
	pages={386-405},
	year={2011},
	doi={doi:10.1016/j.is.2010.08.003},
	publisher={Elsevier}
	}