How to add Microsoft.SharePoint.Client.Runtime reference to project

Hi,

I'm creating an application to get all list items from SharePoint 2010 site using Client object model, and trying to add the following

using Microsoft.SharePoint;

using Microsoft.SharePoint.Client;

using Microsoft.SharePoint.Client.Runtime

I copied the dlls from "C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\ISAPI" folder and pasted in the project's bin folder and add reference to it.

I can see all 3 dll's under project's reference folder in solution explorer. But the the line "using Microsoft.SharePoint.Client.Runtime" is throwing error, saying: The type or namespace 'Runtime' does not exist in the namespace 'Microsoft.SharePoint.Client' (are you missing an assembly reference?)

How can I solve this issue, Please help me

Thank you