TY  - RPRT
TI  - Smallpox--world changes and implications for eradication.
AU  - F L Soper
PY  - 1966
DO  - 10.2105/ajph.56.10.1652
UR  - https://pubmed.ncbi.nlm.nih.gov/5951484/
ID  - 5951484
ER  -