United States. National Bureau of Standards. NBS Metric Kit : Official Metric Information. Washington D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc67329/. Accessed July 29, 2015.
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.