TY  - RPRT
TI  - Vaccine evaluation by case-control or prospective studies.
AU  - G W Comstock
PY  - 1990
DO  - 10.1093/oxfordjournals.aje.a115490
UR  - https://pubmed.ncbi.nlm.nih.gov/2296974/
ID  - 2296974
ER  -