TY  - BOOK
TI  - Stata survey data: Reference manual release 9 
SN  - 1-59718-003-3
U1  - C 519.5'0285 S7972 2005 
PY  - 2005///
CY  - College Station, Tex.
PB  - STATA Corporation
KW  - Ciencias Sociales
KW  - estadisticas métodos
ER  -