Ruoff, H. W. (1909). The standard dictionary of facts: History, language, literature, biography, geography, travel, art, government, politics, industry, invention, commerce, science, education, natural history, statistics and miscellany. Frontier Press Co.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Ruoff, Henry W. The Standard Dictionary of Facts: History, Language, Literature, Biography, Geography, Travel, Art, Government, Politics, Industry, Invention, Commerce, Science, Education, Natural History, Statistics and Miscellany. Buffalo, N.Y.: Frontier Press Co, 1909.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Ruoff, Henry W. The Standard Dictionary of Facts: History, Language, Literature, Biography, Geography, Travel, Art, Government, Politics, Industry, Invention, Commerce, Science, Education, Natural History, Statistics and Miscellany. Frontier Press Co, 1909.