United States. National Bureau of Standards. [United States National Bureau of Standards Metric Conversion Card]. Washington D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc123539/. Accessed August 30, 2014.
Note: Inconsistencies in capitalization and punctuation within the Digital Library may affect this citation. Before using this citation in formal writing, please consult your preferred style manual. More information.