Não informado. (1903). Circular of the Bureau of Standards. U.S. Department of Commerce, National Bureau of Standards.
Chicago-referens (17:e uppl.)Não informado. Circular of the Bureau of Standards. Washington: U.S. Department of Commerce, National Bureau of Standards, 1903.
MLA-referens (8:e uppl.)Não informado. Circular of the Bureau of Standards. U.S. Department of Commerce, National Bureau of Standards, 1903.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.