@misc{indiciaef682fde65553,
  title = {Extended relational operators for statistical data manipulations in medical databases.},
  author = {H H Yao and T S Yamashita},
  year = {1989},
  doi = {10.1016/0010-4809(89)90072-4},
  url = {https://pubmed.ncbi.nlm.nih.gov/2591206/},
  note = {Source identifier: 2591206}
}