TY  - JOUR
TI  - Cluster-Sample Methods in Applied Econometrics
AU  - Jeffrey M. Wooldridge
JO  - American Economic Review
PY  - 2003
VL  - 93
IS  - 2
DO  - 10.1257/000282803321946930
UR  - https://doi.org/10.1257/000282803321946930
ER  -