TY  - BOOK
AU  - Heady, Earl O.
AU  - Johnson, Glenn L. Hardin, Lowell S.
TI  - Resource productivity, returns to scale & farm size
U1  - 658.57 H 432 R 
PY  - 1956///
CY  - USA
PB  - ISCP
KW  - Resourse productivity
ER  -