TY  - DATA
AU  - Rubin, Donald B.
TI  - Matched sampling for causal effects 
SN  - 9780521857628
U1  - 001.433 
PY  - 2006///
CY  - Cambridge, Mass.
PB  - Cambridge University Press
KW  - Muestreo (Estadística)
UR  - http://search.ebscohost.com/login.aspx?direct=true&db=nlebk&AN=171872&site=ehost-live
ER  -