ElementData Source Information
ElementData is based on a wide range of sources, with enhancement at the Wolfram Research Companies by both human and algorithmic processing.
Among principal sources for ElementData are:
Atomic Mass Data Center. "NUBASE." 2003. »
Barbalace, K. "Periodic Table of Elements." 2007. »
Cardarelli, F. Materials Handbook: A Concise Desktop Reference. Springer, 2000.
Lide, D. R. (Ed.). CRC Handbook of Chemistry and Physics. 87th ed. CRC Press, 2006.
Speight, J. Lange's Handbook of Chemistry. McGraw-Hill, 2004.
United Kingdom National Physical Laboratory. "Kaye and Laby Tables of Physical and Chemical Constants." 2007. »
United States National Institute of Standards and Technology. "Atomic Weights and Isotopic Compositions Elements." 2005. »
United States National Institute of Standards and Technology. "NIST Chemistry Webbook." 2005. »
Winter, M. "WebElements." 2007. »