Claudio Cerullo Marco Porta A System for Database Visual Querying and Query Visualization: Complementing Text and Graphics to Increase Expressiveness. 109-113 2007 conf/dexaw/2007 DEXA Workshops http://doi.ieeecomputersociety.org/10.1109/DEXA.2007.24 db/conf/dexaw/dexaw2007.html#CerulloP07