TY  - RPRT
TI  - Control without separate controls: evaluation of vaccine safety using case-only methods.
AU  - C P Farrington
PY  - 2004
DO  - 10.1016/j.vaccine.2004.01.017
UR  - https://pubmed.ncbi.nlm.nih.gov/15121324/
ID  - 15121324
ER  -