TY  - RPRT
TI  - Estimating a treatment effect under biased sampling.
AU  - H Robbins
AU  - C H Zhang
PY  - 1988
DO  - 10.1073/pnas.85.11.3670
UR  - https://pubmed.ncbi.nlm.nih.gov/3375236/
ID  - 3375236
ER  -