Não informado. (1919). Scientific Papers of the Bureau of Standards. U.S. Department of Commerce, National Bureau of Standards.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Scientific Papers of the Bureau of Standards. Washington: U.S. Department of Commerce, National Bureau of Standards, 1919.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Scientific Papers of the Bureau of Standards. U.S. Department of Commerce, National Bureau of Standards, 1919.
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