@misc{indiciae54f0621e5322,
  title = {Frailty models with missing covariates.},
  author = {Amy H Herring and Joseph G Ibrahim and Stuart R Lipsitz},
  year = {2002},
  doi = {10.1111/j.0006-341x.2002.00098.x},
  url = {https://pubmed.ncbi.nlm.nih.gov/11890332/},
  note = {Source identifier: 11890332}
}