Xamarin xaml CoordinatorLayout

I am working for the first time since a while in VS with Xamarin and I am trying to add material design to my app. I added the references to my project (Xamarin.Android.Support and dependencies).

<android.support.design.widget.CoordinatorLayout 
    ..........
</android.support.design.widget.CoordinatorLayout>

and

<android.support.v4.widget.DrawerLayout 
   .......                                     
</android.support.v4.widget.DrawerLayout>

On both I am getting the message:

element is not declared

Do I miss a dependency? I used the xamarin guide & google dev as to get what might be missing.

Maybe someone faced the same issue?