Simona Colucci Tommaso Di Noia Eugenio Di Sciascio Francesco M. Donini Azzurra Ragone Raffaele Rizzi Explanation Services and Request Refinement in User Friendly Semantic-Enabled B2C E-Marketplaces. 13-27 2006 conf/deec/2006 DEECS http://dx.doi.org/10.1007/11780397_2 db/conf/deec/deecs2006.html#ColucciNSDRR06