code: def lookups(self, request, model_admin):
          
  
          output = []
          for i in models.Model.objects.values('information__type').distinct():
              ct = i['information__type']
  
              if ct is not None:
                  ct = ContentType.objects.get(pk=ct)
                  output.append([ct.pk, ct.app_label + '.' + ct.model])
  
          return output
docs: Returns a list of tuples. The first element in each
          tuple is the coded value for the option that will
          appear in the URL query. The second element is the
          human-readable name for the option that will appear
          in the right sidebar.