Missing reference to ReportHelper class

I've inherited a c# project that integrates into AX 2012 R2.  It says it is missing a reference to the ReportHelper and ReportInfo classes.  It looks like they are in the namespace Microsoft.Dynamics.AX.Framework.Reporting.Shared

I can't find any assembly that contains these classes on the box and I know it was working.  Any help in finding the name of the assembly that contains these classes and/or the location would be appreciated!

Jon