TY  - BOOK
AU  - Csorba,Julius J.
TI  - Farm tractors: trends in type, size, age and use 
AV  - S21 .A74 no. 231
PY  - 1960///
CY  - Washington, D.C.
PB  - Agricultural Research Service, U.S. Dept. of Agriculture
KW  - Farm tractors
N1  - Cover title; Bibliography: p. 16
ER  -