@article{elena barbería2006space,
  title={Free-end Space Maintainers: Design, Utilization and Advantages},
  author={elena barbería,tania lucavechi,dora cárdenas,myriam maroto},
  journal={Journal of Clinical Pediatric Dentistry},
  volume={31},
  number={1},
  pages={5--8},
  doi = {10.17796/jcpd.31.1.p87112173240x80m},
  year={2006}
}