TY  - BOOK
AU  - Hanushek,Eric A
AU  - Welch,Finis
ED  - Research and Development Corporation, 
TI  - The use of internal instruments for errors in variables and missing cross products
T2  - The Rand paper series
PY  - 1975///
CY  - Santa Monica, California
PB  - Rand Corporation
KW  - Variables (Mathematics)
KW  - Estimation theory.
KW  - Econometrics.
N1  - Includes bibliographical references
ER  -