JOSEPH EMERSON WORCESTER
SOCIETE DE GEOGRAPHIE DE LILLE
MERRILL R. KAUFMANN
WILLIAM PEARCE
ALFRED WADDINGTON
SOCIETE DE GEOGRAPHIE DE TOULOUSE
THOMAS THOMSON
HAROLD JOHN LUTZ
UNITED STATES SOIL CONSERVATION SERVICE
JOSEPH EMERSON WORCESTER
SOCIETE DE GEOGRAPHIE DE LILLE
MERRILL R. KAUFMANN
WILLIAM PEARCE
ALFRED WADDINGTON
SOCIETE DE GEOGRAPHIE DE TOULOUSE
THOMAS THOMSON
HAROLD JOHN LUTZ
UNITED STATES SOIL CONSERVATION SERVICE