TY  - BOOK
AU  - UNITED STATES DEPARTAMENT OF AGRICULTURE
TI  - Soil. The Yearbook of agriculture 1957 
T2  - 85 Th Congress, IST SESSION, House Document Nº30 
PY  - 1957///
CY  - Washington
PB  - The United States Government Printing Office
KW  - SUELOS
KW  - AGRICULTURA
ER  -