Azzeddine Lazrek; Bruce R. Miller. <a href="http://www.w3.org/TR/2006/NOTE-arabic-math-20060131"><cite>Arabic mathematical notation.</cite></a> 31 January 2006. W3C Note. URL: <a href="http://www.w3.org/TR/2006/NOTE-arabic-math-20060131">http://www.w3.org/TR/2006/NOTE-arabic-math-20060131</a>