Henry Woldmar Ruoff

• The Human Interest Library
• The Standard Dictionary of Facts : History, Language, Literature, Biography, Geography, Travel, Art, Government, Politics, Industry, Invention, ...
• Century Book of Facts
• Leaders of men or, Types and principles of success
• Standard Dictionary of Facts : History, Language, Literature, Biography, Geography, Travel, Art, Government, Politics, Industry, Invention, Commerce, Science, Education, Natural History, Statistics and Miscellany
• The Century book of facts
• The standard dictionary of facts
• The Volume Library