TY  - BOOK
AU  - Ibach, D. B.
AU  - Adams, J. R.
ED  - U. S. Department of Agriculture
ED  - U. S. Department of Agriculture
TI  - Crop yield response to fertilizer in the United States
U1  - 73 SD:338.14 
PY  - 1968///
CY  - Washington
PB  - U. S. Department of Agriculture
ER  -