Here are the few resources by which you can confirm that your article is unique or not.

1. http://www.copyscape.com/
2. http://www.google.com/alerts
3. http://www.plagiarismchecker.com/
4. http://www.dustball.com/cs/plagiarism.checker/
5. http://www.duplichecker.com/
6. http://turnitout.shorturl.com/
7. http://www.degree-essays.com/free-pl...sm-checker.php
8. http://www.plagiarismdetect.com/