TY  - RPRT
TI  - An evaluation of study methods.
AU  - A CIOCCO
AU  - M D RING
PY  - 1951
DO  - 10.2105/ajph.41.8_pt_2.7
UR  - https://pubmed.ncbi.nlm.nih.gov/14847025/
ID  - 14847025
ER  -