PHP code which perfoms this search comes from Vikram's Vaswani article : Use the YouTube API with PHP.
Feed comes from 'http://gdata.youtube.com/feeds/api/videos', method called is 'q', number of returned results is set to 10. The parsing of the XML data is done by simplexml_load_file() function.
Code from here was used by me to develop PHP Simple YouTube API video Search project.
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