@Article{ 
  colgui,
  author = { Colombo, Fabrizio and Guidetti, Davide },
  title = { A unified approach to nonlinear intergodifferential inverse problems of parabolic type },
  journal = { Zeitschrift fur Analysis und ihre Anwendugen },
  year = { 2002 },
  volume = { 21 },
  pages = { 431-464 },
  URL = { http://cvgmt.sns.it/paper/86/ },
  note = { cvgmt preprint}
}