TY  - RPRT
TI  - Epidemiologic surveillance in developing countries.
AU  - R R Frerichs
PY  - 1991
DO  - 10.1146/annurev.pu.12.050191.001353
UR  - https://pubmed.ncbi.nlm.nih.gov/2049138/
ID  - 2049138
ER  -