TY  - GEN
AU  - Hanson,H.C.
TI  - American Institute of Crop Ecology, study series: No. 30B 
PY  - 1963///
CY  - Washington
KW  - Agricultural Ecology
KW  - Crop Ecology
KW  - Diseases
KW  - Pests
KW  - Economic
KW  - Plants
ER  -