Standard time and frequency signal service (STFS): In the United States, standardtime and frequency signals, broadcast on very precise carrier frequencies by the U.S. Naval Observatory and the National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards (NBS).
... 2000 and the 2003 U.S. Department of State website.
External Links
Brasil.gov.br (http://www.brasil.gov.br) - Official governmental portal (in Portuguese)
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