Flavio Chierichetti Silvio Lattanzi Federico Mari Alessandro Panconesi On placing skips optimally in expectation. 15-24 2008 conf/wsdm/2008 WSDM http://doi.acm.org/10.1145/1341531.1341537 db/conf/wsdm/wsdm2008.html#ChierichettiLMP08