TY  - RPRT
TI  - A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.
AU  - M E Charlson
AU  - P Pompei
AU  - K L Ales
AU  - C R MacKenzie
PY  - 1987
DO  - 10.1016/0021-9681(87)90171-8
UR  - https://pubmed.ncbi.nlm.nih.gov/3558716/
ID  - 3558716
ER  -