@INPROCEEDINGS{trefzer:2008:hifffitness,
  author = {Kuyucu, T\"uze and Trefzer, Martin A. and Greensted, Andy J. and Miller, Julian F. and Tyrrell, Andy M.},
  title = {Fitness Functions for the Unconstrained Evolution of Digital Circuits},
  booktitle = {Proceedings of the 9th IEEE World Congress on Computational Intelligence (WCCI 2008)},
  year = {2008},
  pages = {2589-2596},
  address = {Hong Kong},
  month = {June},
}