How do I access a resource defined in App.xaml?

Hi,

I have been trying to follow various guides I've found on the internet about how to access resources defined in an App.xaml file from a ContentPage but none of the method work. Is there something different about Xamarin's flavour of XAML that changes how to access application-wide resources?

(Note: I know a Xamarin PCL does not normally contain an App.xaml file, but I created one specifically so I could have application-wide resources in a XAML file.)

Kind wishes ~ Patrick