Baruch Awerbuch Aviv Nisgav Boaz Patt-Shamir Asynchronous Active Recommendation Systems. 48-61 2007 OPODIS http://dx.doi.org/10.1007/978-3-540-77096-1_4 conf/opodis/2007 db/conf/opodis/opodis2007.html#AwerbuchNP07