TY  - BOOK
AU  - Bertrand, Marianne
AU  - Mullainathan Sendhil
AU  - Duflo Esther
AU  - National Bureau Of Economic Research
TI  - How much should we trust differences-in-differences estimates?
T2  - NBER working papers
PY  - 2002///
CY  - Cambridge, MA
PB  - NBER
ER  -