TY  - RPRT
TI  - Relation between experimental and non-experimental study designs. HB vaccines: a case study.
AU  - T Jefferson
AU  - V Demicheli
PY  - 1999
DO  - 10.1136/jech.53.1.51
UR  - https://pubmed.ncbi.nlm.nih.gov/10326054/
ID  - 10326054
ER  -