@namespace("eu.dnetlib.iis.citationmatching.direct.schemas")
protocol IIS{

	record ReferenceMetadata {
        // reference position in the bibliography
        int position;
        // external identifiers
		union { null , map<string> } externalIds = null;
    }
    
    record DocumentMetadata {
        string id;
//      alternative identifier (e.g. internal publisher's identifiers)
        union { null , map<string> } externalIdentifiers = null;
//      detailed publication type name, originates from extracted metadata
        union { null , string } publicationTypeName = null;
        array<ReferenceMetadata> references;
    }
}