diff --git a/parser/src/main/resources/py/urltool.py b/parser/src/main/resources/py/urltool.py
index 023989d..4ed6054 100644
--- a/parser/src/main/resources/py/urltool.py
+++ b/parser/src/main/resources/py/urltool.py
@@ -5,6 +5,7 @@ import base64
 
 
 """
+https://github.com/chenhal/short_url
 """
 headers = {
     'Cookie': 'SUB=',