Patrick Schmitz; Aaron Cohen. <a href="http://www.w3.org/TR/2001/REC-smil-animation-20010904"><cite>SMIL Animation.</cite></a> 4 September 2001. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2001/REC-smil-animation-20010904">http://www.w3.org/TR/2001/REC-smil-animation-20010904</a>