Other data providers

ThomsonReuters have an API that looks useful: http://ip-science.interest.thomsonreuters.com/data-integration

But the data policy: http://ip-science.interest.thomsonreuters.com/data_policy

says:

Times Cited counts can be displayed dynamically but not stored in a local system. Times cited counts cannot be harvested, aggregated, or manipulated.

So probably not too helpful for us.