Component S2 of <a href="https://en.wikipedia.org/wiki/International_Commission_on_Illumination" class="extiw" title="w:International Commission on Illumination">CIE</a> <a href="https://en.wikipedia.org/wiki/standard_illuminant" class="extiw" title="w:standard illuminant">illuminant series D</a>
adoniscik
2008-04-04
<a rel="nofollow" class="external text" href="http://www.cie.co.at/publ/abst/datatables15_2004/s2.txt">Freely available at CIE</a>