TY  - RPRT
TI  - Mass vaccination: when and why.
AU  - D L Heymann
AU  - R B Aylward
PY  - 2006
DO  - 10.1007/3-540-36583-4_1
UR  - https://pubmed.ncbi.nlm.nih.gov/16989261/
ID  - 16989261
ER  -