@Article{PittsAM:alpsri,
  author =	 {A. M. Pitts},
  title =	 {Alpha-Structural Recursion and Induction},
  journal =	 {Journal of the {ACM}},
  year =	 2006,
  volume =	 53,
  pages =	 {459--506},
  doi =		 {http://doi.acm.org/10.1145/1147954.1147961}
}