1. Gartner, J.S.: Gartner: clouds, virtualization help pay for IT projects. http://itmanagement.earthweb.com/netsys/article.php/3921821/Gartner-Clouds-Virtualization-Help-Pay-for-IT-Projects.htm (2011)
2. Amazon Web Services (AWS). http://aws.amazon.com
3. Microsoft Azure. http://www.microsoft.com/azure/
4. Force.com platform. http://www.force.com/
5. Google Docs Apps for Business. http://www.google.com/apps