REST Output

I'm pretty new to REST and I've figured out how to execute a workflow via REST.  Works great, but what I'm trying to figure out is how to get results back.  I've got a workflow that outputs all the VMs in a cluster into an output parameter called vmArray.  I can execute the workflow via REST just fine.  I can see the execution staus, etc.  How do I actually retrieve the contents of the variable though?  I couldn't find an example of this online.  Any help is appreciated.  Thanks,

Mike