@inproceedings{ijcai1973p84,
  title     = {Backtracking in MLISP2: an efficient backtracking method for LISP},
  author    = {Smith, David Canfield and Enea, Horace J.},
  booktitle = {Proceedings of the Third International Joint Conference on
               Artificial Intelligence, {IJCAI-73}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Nils J. Nilsson},
  pages     = {677--684},
  year      = {1973},
  month     = {8},
  note      = {Hardware and Software for A.I.},
  url       = {https://ijcai.org/proceedings/1973/84},
}