@Article{Barbanera+95,
  author = 	 {Franco Barbanera and Mariangiola Dezani-Ciancaglini and Ugo de'Liguorio},
  title = 	 {Intersection and Union Types: Syntax and Semantics},
  journal = 	 {Information and Computation},
  year = 	 1995,
  volume =	 119,
  number =	 2,
  pages =	 {202--230},
  month =	 {June}
}