diff --git a/ippisite/ippidb/models.py b/ippisite/ippidb/models.py
index a75b3c91a8f6567ce9f088bab93e39ec1f0a63a9..fb8e8ce6e5a54507de83d061eeace5c1c2da6d09 100644
--- a/ippisite/ippidb/models.py
+++ b/ippisite/ippidb/models.py
@@ -43,8 +43,6 @@ class Bibliography(AutoFillableModel):
     Bibliography references
     (publications or patents)
     """
-    class Meta:
-        unique_together = ('source', 'id_source',)
     SOURCES = (
         ('PM', 'PubMed ID'),
         ('PT', 'Patent'),