Get other project's app.config value in a VS solution

Hi all,
     Let's a say I have two project's in my solution. Each have their own app.config files. Project 1 has been referenced in project 2. 
     Solution
         a) project 1
             app.config
         b) Project 2
            References: Project 1
            app.config
   Now my question is how can I get the app.config value of project 1 from within the Project 2.
 
Thanks in advance
 
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