TY  - RPRT
TI  - Frailty models with missing covariates.
AU  - Amy H Herring
AU  - Joseph G Ibrahim
AU  - Stuart R Lipsitz
PY  - 2002
DO  - 10.1111/j.0006-341x.2002.00098.x
UR  - https://pubmed.ncbi.nlm.nih.gov/11890332/
ID  - 11890332
ER  -