@article\{ddgl-gvtwc-07
, author =	"Emilio {Di Giacomo} and Walter Didimo and Luca Grilli and Giuseppe Liotta"
, title =	"Graph Visualization Techniques for Web Clustering Engines"
, journal =	"IEEE Transactions on Visualization and Computer Graphics"
, volume =	13
, number =	"2"
, pages =	"294-304"
, year =	2007
}