@article{Romero_2013,
  title={{A Globally Exponentially Stable Tracking Controller for Mechanical Systems with Friction Using Position Feedback}},
  volume={46},
  ISSN={1474-6670},
  DOI={10.3182/20130904-3-fr-2041.00174},
  number={23},
  journal={IFAC Proceedings Volumes},
  publisher={Elsevier BV},
  author={Romero, José Guadalupe and Ortega, Romeo},
  year={2013},
  pages={371--376}
}