@misc{indiciae3cfbfcee07ba,
  title = {Observation services--past, present, and future.},
  author = {M A Ross and R J Zalenski},
  year = {2001},
  doi = {10.1016/s0002-9343(01)00624-6},
  url = {https://pubmed.ncbi.nlm.nih.gov/11239856/},
  note = {Source identifier: 11239856}
}