REST API Get PBI's/WorkItems with "Done" status in a specific Iteration for a team project.

I just want to use the REST API to do something like:

http://site/tfs/SomeCollection/TeamProject/_apis/wit/workitems?Status=Done&Iteration=3.2.13&api-version=1.0

For some reason, you can only look up WorkItems with specific IDs.  Well how do you GET those IDs Restfully?

What I want to do is: when I run my application, I search for completed tasks/pbi's in a specified iteration/sprint, and report on them in a custom way in my application.