Benjamin Piwowarski Mounia Lalmas Ingo Frommholz Keith van Rijsbergen Exploring a multidimensional representation of documents and queries. 57-60 2010 RIAO http://portal.acm.org/citation.cfm?id=1937067&CFID=17354760&CFTOKEN=88565769 conf/riao/2010 db/conf/riao/riao2010.html#PiwowarskiLFR10