I would assume the usage of "xyz" is intended to represent a "generic" name of a class. For your project to work the libraries referenced by your deployed product must exist on the host server. While one could rely upon GAC deployed libraries that might not be wise in your case.
I assume you have seen the "copy local" in your Visual Studio references before? This is an example where you would want to use that feature. I, for example, assume the default .NET libraries are present (not always a wise thing). I do however right click on all non-standards references (such as Telerik) and select "copy local". That way when I publish my app, a copy of the required library is also deployed with your files.