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 Company.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিRuoff, 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 Company, 1909.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিRuoff, 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 Company, 1909.