@InProceedings{ariola-felleisen-maraist-odersky-wadler:call-by-need,
  author = 	 "Zena M. Ariola and Matthias Felleisen and John
		  Maraist and Martin Odersky and Philip Wadler",
  title = 	 "A Call-By-Need Lambda Calculus",
  booktitle =	 "Proc. 22nd {ACM} Symposium on Principles of
		  Programming Languages",
  year =	 1995,
  pages =        {233-246},
  month =	 "January"
}