TY  - RPRT
TI  - Ecological effects in multi-level studies.
AU  - T A Blakely
AU  - A J Woodward
PY  - 2000
DO  - 10.1136/jech.54.5.367
UR  - https://pubmed.ncbi.nlm.nih.gov/10814658/
ID  - 10814658
ER  -