Per anno

@phdthesis {D-phdthesis,
  author       = {Denti,Enrico},
  title        = {Coordination of Heterogeneous Multi-Agent Systems: Programming the Interaction},
  year         = {1998},
  school       = {Dept. of Electronics, Computer Science and Systems (DEIS)
          Viale Risorgimento 2, I-40136 Bologna, Italy},
}

@misc {D-phdthesisAbstract,
  author       = {Denti,Enrico},
  title        = {Coordination of Heterogeneous Multi-Agent Systems: Programming the Interaction
          (Abstract of Ph.D. Thesis)},
  year         = {1998},
  howpublished = {AI*IA Notizie, Anno XI, N° 4},
  number       = {4},
  month        = {December},
}