Johan Hjelm; Lalitha Suryanarayana. <a href="http://www.w3.org/TR/2001/NOTE-CCPP-COORDINATION-20011220"><cite>CC/PP Implementors Guide: Harmonization with Existing Vocabularies and Content Transformation Heuristics.</cite></a> 20 December 2001. W3C Note. URL: <a href="http://www.w3.org/TR/2001/NOTE-CCPP-COORDINATION-20011220">http://www.w3.org/TR/2001/NOTE-CCPP-COORDINATION-20011220</a>