@misc{indiciae213d58d2c31b,
  title = {Instability in spondylolisthesis.},
  author = {O Friberg},
  year = {1991},
  doi = {10.3928/0147-7447-19910401-11},
  url = {https://pubmed.ncbi.nlm.nih.gov/2038581/},
  note = {Source identifier: 2038581}
}