Francesco Gargiulo Antonio Penta Antonio Picariello Carlo Sansone Using Heterogeneous Features for Anti-spam Filters. 670-674 2008 DEXA Workshops http://doi.ieeecomputersociety.org/10.1109/DEXA.2008.90 conf/dexaw/2008 db/conf/dexaw/dexaw2008.html#GargiuloPPS08