@InCollection{YardeniShapiro92,
  author = 	 {Eyal Yardeni and Ehud Shapiro},
  title = 	 {A Type System for Logic Programs},
  booktitle = 	 {Concurrent Prolog},
  pages =	 {211--244},
  publisher =	 {MIT Press},
  year =	 1987,
  editor =	 {Ehud Shapiro},
  volume =	 2,
  chapter =	 8
}