@article{TovMurLav07,
  author={B.Tovar and R. Murrieta-Cid and S. M. LaValle},
  title={Distance-Optimal Navigation in an Unknown Environment without
  Sensing Distances},
  journal={IEEE Transactions on Robotics},
  month={June},
  pages={506--518},
  volume=23,
  number=3,
  year={2007}}