@misc{indiciaed842710d4828,
  title = {OPALS study.},
  author = {T O Cheng},
  year = {1999},
  doi = {10.1016/s0196-0644(99)70403-8},
  url = {https://pubmed.ncbi.nlm.nih.gov/9988665/},
  note = {Source identifier: 9988665}
}