--- a/src/pyams_content_es/document.py	Wed Nov 14 17:45:43 2018 +0100
+++ b/src/pyams_content_es/document.py	Wed Nov 14 17:46:37 2018 +0100
@@ -12,24 +12,19 @@
 
 __docformat__ = 'restructuredtext'
 
+from pyramid.threadlocal import get_current_registry
+from pyramid_es.mixin import ESField, ESMapping, ElasticMixin as ElasticMixinBase
+from zope.interface import classImplements
+from zope.intid.interfaces import IIntIds
 
-# import standard library
-
-# import interfaces
+from pyams_content.shared.common import WfSharedContent
 from pyams_content.shared.common.interfaces import IWfSharedContent
 from pyams_content.shared.common.interfaces.types import IWfTypedSharedContent
 from pyams_content_es.interfaces import IDocumentIndexInfo, IDocumentIndexTarget
 from pyams_sequence.interfaces import ISequentialIdInfo
-from pyams_workflow.interfaces import IWorkflowState
-from zope.intid.interfaces import IIntIds
-
-# import packages
-from pyams_content.shared.common import WfSharedContent
 from pyams_utils.adapter import adapter_config
 from pyams_utils.registry import get_utility
-from pyramid.threadlocal import get_current_registry
-from pyramid_es.mixin import ElasticMixin as ElasticMixinBase, ESMapping, ESField
-from zope.interface import classImplements
+from pyams_workflow.interfaces import IWorkflowState
 
 
 class ElasticMixin(ElasticMixinBase):
@@ -37,28 +32,36 @@
 
     @property
     def id(self):
-        return '{oid}.{version}'.format(oid=ISequentialIdInfo(self).hex_oid,
-                                        version=IWorkflowState(self).version_id)
+        oid = ISequentialIdInfo(self).hex_oid
+        state = IWorkflowState(self, None)
+        if state is None:
+            return oid
+        else:
+            return '{oid}.{version}'.format(oid=oid, version=state.version_id)
 
     @property
     def internal_id(self):
         intids = get_utility(IIntIds)
         return intids.register(self)
 
+    @property
+    def reference_id(self):
+        return ISequentialIdInfo(self).hex_oid
+
     def elastic_mapping(self):
         return IDocumentIndexInfo(self)
 
     def elastic_document(self):
         document_info = super(ElasticMixin, self).elastic_document()
         registry = get_current_registry()
-        for name, adapted in registry.getAdapters((self, ), IDocumentIndexInfo):
+        for name, adapted in registry.getAdapters((self,), IDocumentIndexInfo):
             if not name:
                 continue
             document_info.update(adapted)
         return document_info
 
 
-WfSharedContent.__bases__ += (ElasticMixin, )
+WfSharedContent.__bases__ += (ElasticMixin,)
 classImplements(WfSharedContent, IDocumentIndexTarget)
 
 
@@ -66,6 +69,7 @@
 def wf_shared_content_index_info(content):
     return ESMapping(analyzer='content',
                      properties=ESMapping(ESField('internal_id'),
+                                          ESField('reference_id'),
                                           ESField('content_type'),
                                           ESField('title', boost=3.0),
                                           ESField('short_name'),
@@ -77,6 +81,7 @@
 def wf_typed_shared_content_index_info(content):
     return ESMapping(analyzer='content',
                      properties=ESMapping(ESField('internal_id'),
+                                          ESField('reference_id'),
                                           ESField('content_type'),
                                           ESField('data_type'),
                                           ESField('title', boost=3.0),