UNITED STATES ECONOMIC RESEARCH SERVICE
WILLIAM CHANNING WOODBRIDGE
STE. DETUDES SCIENTIFIQUES DANGERS
UNITED STATES SOIL CONSERVATION SERVICE
UNKNOWN AUTHOR
WILLIAM BELL DAWSON
UNITED STATES ECONOMIC RESEARCH SERVICE
WILLIAM CHANNING WOODBRIDGE
STE. DETUDES SCIENTIFIQUES DANGERS
UNITED STATES SOIL CONSERVATION SERVICE
UNKNOWN AUTHOR
WILLIAM BELL DAWSON