Lichan Hong Ed Huai-hsin Chi Raluca Budiu Peter Pirolli Les Nelson SparTag.us: a low cost tagging system for foraging of web content. 65-72 2008 AVI http://doi.acm.org/10.1145/1385569.1385582 conf/avi/2008 db/conf/avi/avi2008.html#HongCBPN08