TY  - RPRT
TI  - The case-control study and retrospective controls.
AU  - J I Mann
AU  - M P Vessey
PY  - 1979
DO  - 10.1136/bmj.2.6203.1507-a
UR  - https://pubmed.ncbi.nlm.nih.gov/526828/
ID  - 526828
ER  -