by National Association of Office Managers (U.S.). National Conference

1922

by National Research Council (U.S.), Callie Hull

1926

by National Association of Retail Druggists (U.S.)

1930

by National Electric Light Association

1906

by National Electric Light Association

1903

by National Electric Light Association

1902

by National Electric Light Association. Convention

1929

by National Cash Register Company

1904

by National Electric Light Association

1920

by National Safety Council

1918

by National Retail Merchants Association (U.S.)

1925

by National Industrial Conference Board

1928