TY  - RPRT
TI  - Case-control studies.
AU  - R L Cumming
AU  - J L Kelsey
PY  - 1989
DO  - 10.1093/ije/18.3.725
UR  - https://pubmed.ncbi.nlm.nih.gov/2807683/
ID  - 2807683
ER  -