TY  - BOOK
AU  - "NATIONAL BUREAU OF ECONOMIC RESEARCH,INC."
ED  - "NATIONAL BUREAU OF ECONOMIC RESEARCH,INC."
TI  - 51st annual report 1971
U1  - "X.73.N71r, L1" 
PY  - 1971///
CY  - New
PB  - York NBER      
ER  -