TY  - BOOK
AU  - Sunil Kumar
TI  - Productivity and factor substitiution :  Theory and   
SN  - 8176293520
U1  - X:89P:(B), P1 
PY  - 2001///
CY  -  New Delhi 
PB  - Deep and Deep Publication India     
KW  - Production Engeeniring
ER  -