Pierpaolo Basile Marco Degemmis Pasquale Lops Giovanni Semeraro OTTHO: On the Tip of My THOught. 710-713 2009 ECML/PKDD (2) http://dx.doi.org/10.1007/978-3-642-04174-7_46 conf/pkdd/2009-2 db/conf/pkdd/pkdd2009-2.html#BasileDLS09