@prefix : <http://namespace1.org/> .
@prefix ns3: <http://namespace3.org/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . 
@prefix owl:  <http://www.w3.org/2002/07/owl#> . 
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix dcterms: <http://purl.org/dc/terms/> . 

:itemA1 dcterms:source <http://sourceA/1> .