diff --git a/pandora/annotation/models.py b/pandora/annotation/models.py
index dfd9a188..2df53b63 100644
--- a/pandora/annotation/models.py
+++ b/pandora/annotation/models.py
@@ -183,6 +183,7 @@ class Annotation(models.Model):
             # update matches in bulk if called from load_subtitles
             if not delay_matches:
                 self.update_matches()
+            self.update_documents()
 
     def update_matches(self):
         from place.models import Place
@@ -247,6 +248,20 @@ class Annotation(models.Model):
                 for e in a_matches.all():
                     e.update_matches(Annotation.objects.filter(pk=self.id))
 
+    def update_documents(self):
+        from document.models import Document
+        from document.utils import get_documents
+        old = [d.id for id in self.documents.all()]
+        current = get_documents(self.value) if self.value else []
+        removed = list(set(old) - set(current))
+        added = list(set(current) - set(old))
+        if removed:
+            for document in Document.objects.filter(id__in=removed):
+                self.documents.remove(document)
+        if added:
+            for document in Document.objects.filter(id__in=added):
+                self.documents.add(document)
+
     def delete(self, *args, **kwargs):
         with transaction.atomic():
             super(Annotation, self).delete(*args, **kwargs)
diff --git a/pandora/document/management/commands/rebuild_documentfind.py b/pandora/document/management/commands/rebuild_documentfind.py
index 05af9d84..d297a566 100644
--- a/pandora/document/management/commands/rebuild_documentfind.py
+++ b/pandora/document/management/commands/rebuild_documentfind.py
@@ -27,3 +27,11 @@ class Command(BaseCommand):
                 i.save()
             except:
                 pass
+        import annotation.models
+        ids = [i['id'] for i in annotation.models.Annotation.objects.all().values('id')]
+        for id in ids:
+            try:
+                a = annotation.models.Annotation.objects.get(id=id)
+                a.update_documents()
+            except:
+                pass
diff --git a/pandora/document/migrations/0010_auto_20170126_1528.py b/pandora/document/migrations/0010_auto_20170126_1528.py
new file mode 100644
index 00000000..fd68be50
--- /dev/null
+++ b/pandora/document/migrations/0010_auto_20170126_1528.py
@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.4 on 2017-01-26 15:28
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('annotation', '0003_auto_20160219_1537'),
+        ('document', '0009_add_group'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='document',
+            name='annotations',
+            field=models.ManyToManyField(related_name='documents', to='annotation.Annotation'),
+        ),
+        migrations.AddField(
+            model_name='document',
+            name='linked_documents',
+            field=models.ManyToManyField(related_name='linking_documents', to='document.Document'),
+        ),
+        migrations.AlterField(
+            model_name='document',
+            name='ratio',
+            field=models.FloatField(default=-1),
+        ),
+    ]
diff --git a/pandora/document/models.py b/pandora/document/models.py
index c7ded012..ef2e491e 100644
--- a/pandora/document/models.py
+++ b/pandora/document/models.py
@@ -23,6 +23,7 @@ from oxdjango import fields
 from oxdjango.sortmodel import get_sort_field
 from person.models import get_name_sort
 from item.models import Item
+from annotation.models import Annotation
 from archive.extract import resize_image
 from archive.chunk import save_chunk
 
@@ -59,6 +60,8 @@ class Document(models.Model):
     uploading = models.BooleanField(default=False)
 
     items = models.ManyToManyField(Item, through='ItemProperties', related_name='documents')
+    annotations = models.ManyToManyField(Annotation, related_name='documents')
+    linked_documents = models.ManyToManyField('Document', related_name='linking_documents')
 
     rightslevel = models.IntegerField(db_index=True, default=0)
     data = fields.DictField(default={})
@@ -195,10 +198,7 @@ class Document(models.Model):
             setattr(s, name, value)
 
         def get_value(source, key):
-            if 'value' in key and 'layer' in key['value']:
-                value = [a.value for a in self.annotations.filter(layer=key['value']['layer']).exclude(value='')]
-            else:
-                value = self.get_value(source)
+            value = self.get_value(source)
             return value
 
         def get_words(source, key):
@@ -242,10 +242,7 @@ class Document(models.Model):
                     set_value(s, name, value)
                 elif sort_type in ('length', 'integer', 'time', 'float'):
                     # can be length of strings or length of arrays, i.e. keywords
-                    if 'layer' in key.get('value', []):
-                        value = self.annotations.filter(layer=key['value']['layer']).count()
-                    else:
-                        value = self.get_value(source)
+                    value = self.get_value(source)
                     if isinstance(value, list):
                         value = len(value)
                     set_value(s, name, value)
@@ -284,6 +281,7 @@ class Document(models.Model):
                 self.update_find()
                 self.update_facets()
         self.update_matches()
+        self.update_linked_documents()
 
     def __unicode__(self):
         return self.get_id()
@@ -580,35 +578,44 @@ class Document(models.Model):
         return urls
 
     def referenced(self):
-        import annotation.models
-        import item.models
         result = {}
-        result['items'] = [i.get_json(keys=['id', 'title']) for i in self.items.all().order_by('sort__title')]
-        urls = self.urls()
-        # annotations
-        q = Q()
-        for url in urls:
-            q |= Q(value__contains=url)
-        qs = annotation.models.Annotation.objects.filter(q)
-        result['annotations'] = [a.json(keys=['id', 'title', 'in']) for a in qs]
-        # documents
-        q = Q()
-        for url in urls:
-            q |= Q(data__contains=url)
-        qs = Document.objects.filter(q)
-        result['documents'] = [d.json(keys=['id', 'title']) for d in qs]
-
-        result['entities'] = [e.json(keys=['id', 'name']) for e in self.entities.all()]
+        result['items'] = [
+            i.get_json(keys=['id', 'title'])
+            for i in self.items.all().order_by('sort__title')
+        ]
+        result['annotations'] = [
+            a.json(keys=['id', 'title', 'in'])
+            for a in self.annotations.all().order_by('start', 'end')
+        ]
+        result['documents'] = [
+            d.json(keys=['id', 'title'])
+            for d in self.linking_documents.all().order_by('sort__title')
+        ]
+        result['entities'] = [
+            e.json(keys=['id', 'name'])
+            for e in self.entities.all()
+        ]
         return result
 
+    def update_linked_documents(self):
+        if self.extension == 'html':
+            old = [d.id for id in self.linked_documents.all()]
+            current = utils.get_documents(self.data['text'])
+            removed = list(set(old) - set(current))
+            added = list(set(current) - set(old))
+            if removed:
+                for document in Document.objects.filter(id__in=removed):
+                    self.linked_documents.remove(document)
+            if added:
+                for document in Document.objects.filter(id__in=added):
+                    self.linked_documents.add(document)
+
     def update_matches(self):
-        import annotation.models
-        import item.models
         urls = self.urls()
         matches = self.items.count() + self.entities.count()
         for url in urls:
-            matches += annotation.models.Annotation.objects.filter(value__contains=url).count()
-            matches += item.models.Item.objects.filter(data__contains=url).count()
+            matches += Annotation.objects.filter(value__contains=url).count()
+            matches += Item.objects.filter(data__contains=url).count()
             matches += Document.objects.filter(extension='html', data__contains=url).count()
         if matches != self.matches:
             Document.objects.filter(id=self.id).update(matches=matches)
diff --git a/pandora/document/utils.py b/pandora/document/utils.py
index a33afcda..70eb3da4 100644
--- a/pandora/document/utils.py
+++ b/pandora/document/utils.py
@@ -1,9 +1,10 @@
 # -*- coding: utf-8 -*-
 # vi:si:et:sw=4:sts=4:ts=4
-
-
+import re
 import subprocess
 
+import ox
+
 from item.utils import sort_title, sort_string, get_by_id
 
 def pdfpages(pdf):
@@ -28,3 +29,8 @@ def extract_pdfpage(pdf, image, page):
     p = subprocess.Popen(cmd, close_fds=True)
     p.wait()
     return image
+
+def get_documents(text):
+    ids = re.compile('/documents/([A-Z]+)').findall(text)
+    ids += re.compile('/document/([A-Z]+)').findall(text)
+    return [ox.fromAZ(id) for id in set(ids)]