def get_resources(cls):
        """Returns external resources."""
        my_plurals = resource_helper.build_plural_mappings(
            {}, RESOURCE_ATTRIBUTE_MAP)
        attributes.PLURALS.update(my_plurals)
        attr_map = RESOURCE_ATTRIBUTE_MAP
        ext_resources = resource_helper.build_resource_info(my_plurals,
                                                            attr_map,
                                                            constants.A10_CERTIFICATE)

        return ext_resources
Returns external resources.