@article{Meghini01,
   author       = {Carlo Meghini and Fabrizio Sebastiani and Umberto Straccia},
   title        = {A model of multimedia information retrieval},
   journal      = {Journal of the ACM},
   year         = {2001},
   volume       = {48},
   number       = {5},
   pages        = {909--970}
}