TY  - BOOK
AU  - Heckman, James J.
AU  - Leamer, Edward E.
TI  - Handbook of econometrics, Vol 6A
T2  - Handbooks in Economics 
SN  - 9780444506313
U1  - 330.015195 
PY  - 2007///
CY  - Amsterdam
PB  - North-Holland
ER  -