Fix links to ISO year week number notation
diff --git a/docs/examples.rst b/docs/examples.rst
index 8ca6a87..2b98dbd 100644
--- a/docs/examples.rst
+++ b/docs/examples.rst
@@ -138,7 +138,7 @@
     datetime.date(2003, 9, 24)
 
 Following
-[http://www.cl.cam.ac.uk/~mgk25/iso-time.html ISO year week number notation]
+`ISO year week number notation <https://www.cl.cam.ac.uk/~mgk25/iso-time.html>`_
 find the first day of the 15th week of 1997.
 
 .. doctest:: relativedelta