I am gearing-up an article syndication site. Over the months, a few articles were added weekly and were usually quickly indexed by Google- except three. These three articles were uploaded over three months ago, they are of high quality, and passed Copyscape (I checked several times). I can't really think of a reason why Google seemingly refuses to index these three articles. I cannot syndicate them until they are indexed (as I must establish copyright). What should I do?