WonSuk Lee; Felix Sasaki; Tobias B&#252;rger. <a href="http://www.w3.org/TR/2009/WD-media-annot-reqs-20090119"><cite>Use Cases and Requirements for Ontology and API for Media Object 1.0.</cite></a> 19 January 2009. W3C Working Draft. (Work in progress.) URL: <a href="http://www.w3.org/TR/2009/WD-media-annot-reqs-20090119">http://www.w3.org/TR/2009/WD-media-annot-reqs-20090119</a>