TY  - RPRT
TI  - Risk stratification for open heart surgery.
AU  - D J Spiegelhalter
PY  - 1992
DO  - 10.1136/bmj.305.6867.1500-a
UR  - https://pubmed.ncbi.nlm.nih.gov/1493411/
ID  - 1493411
ER  -