TY  - RPRT
TI  - The case control or retrospective study in retrospect.
AU  - M W Smith
PY  - 1981
DO  - 10.1002/j.1552-4604.1981.tb01765.x
UR  - https://pubmed.ncbi.nlm.nih.gov/7263924/
ID  - 7263924
ER  -