Where are "Resources" stored?

I need to add some "Resources". If I use the 'Create' button and manually add them where are these stored in code base. 

Our Production environment is missing some resources. I want to add them in my dev. environment and the export the XML but I can't find where would the new enteries be stored.


"Resources" comes from mpp_machine item , guessing from the icon, which is poly-source item to mpp_Resource if that helps. 

Thanks!