diff --git a/pymisp/api.py b/pymisp/api.py
index c04e77d..cc63f86 100644
--- a/pymisp/api.py
+++ b/pymisp/api.py
@@ -553,6 +553,28 @@ class PyMISP(object):
         attributes = []
         attributes.append(self._prepare_full_attribute('Attribution', 'threat-actor', target, to_ids, comment, distribution))
         return self._send_attributes(event, attributes, proposal)
+        
+    # ##### Internal reference attributes #####
+    
+    def add_internal_link(self, event, reference, to_ids=False, comment=None, distribution=None, proposal=False):
+        attributes = []
+        attributes.append(self._prepare_full_attribute('Internal reference', 'link', reference, to_ids, comment, distribution))
+        return self._send_attributes(event, attributes, proposal)
+        
+    def add_internal_comment(self, event, reference, to_ids=False, comment=None, distribution=None, proposal=False):
+        attributes = []
+        attributes.append(self._prepare_full_attribute('Internal reference', 'comment', reference, to_ids, comment, distribution))
+        return self._send_attributes(event, attributes, proposal)
+        
+    def add_internal_text(self, event, reference, to_ids=False, comment=None, distribution=None, proposal=False):
+        attributes = []
+        attributes.append(self._prepare_full_attribute('Internal reference', 'text', reference, to_ids, comment, distribution))
+        return self._send_attributes(event, attributes, proposal)
+        
+    def add_internal_other(self, event, reference, to_ids=False, comment=None, distribution=None, proposal=False):
+        attributes = []
+        attributes.append(self._prepare_full_attribute('Internal reference', 'other', reference, to_ids, comment, distribution))
+        return self._send_attributes(event, attributes, proposal)
 
     # ##################################################
     # ######### Upload samples through the API #########