@conference {li2011exploring,
	title = {Exploring categorization property of social annotations for information retrieval},
	booktitle = {Proceedings of the 20th ACM international conference on Information and knowledge management},
	year = {2011},
	pages = {557{\textendash}562},
	publisher = {ACM},
	organization = {ACM},
	author = {Li, Peng and Wang, Bin and Jin, Wei and Jian-Yun Nie and Shi, Zhiwei and He, Ben}
}
