TY  - BOOK
AU  - United States,Dept. of Agriculture.
TI  - Laying out fields for tractor plowing. rev
U1  - 631.312 
PY  - 1954///
CY  - Washington
PB  - U.S. Govt. Printing office.
KW  - Agriculture
KW  - Machinery,Tools
KW  - Tractor plowing
ER  -