@article{BelDiNoGeo:99,
  journal = {J. Appl. Non-Classical Logics},
  volume = {9},
  title = {Perfect {MV}-algebras and {$l$}-rings},
  year = {1999},
  fjournal = {Journal of Applied Non-Classical Logics},
  pages = {159--172},
  number = {1},
  author = {Belluce, Lawrence P. and Di Nola, Antonio and Georgescu, George},
  note = {Multi-valued logics},
}