| 000 | 00430 a2200121 4500 | ||
|---|---|---|---|
| 100 | 1 | _aHeady, E.O. | |
| 245 | 1 | _aResource productivity and returns on 160-acre farms in North-Central Iowa (A production function study of marginal returns of farms with fixed plants) | |
| 260 |
_aAmes _c1954 |
||
| 300 | _a1069-1096 p. | ||
| 440 | _aIowa Agricultural Expriment Station. Research Bulletin No. 412 | ||
| 942 |
_2udc _cB |
||
| 901 | _a43135 | ||
| 999 |
_c55726 _d55726 |
||