diff --git a/src/Years/Y2015/Day11.md b/src/Years/Y2015/Day11.md
index 4be5ba5..0f6ccc6 100644
--- a/src/Years/Y2015/Day11.md
+++ b/src/Years/Y2015/Day11.md
@@ -222,4 +222,6 @@ day11 : Day
 day11 = First 11 part1
 -->
 
+## References
+
 [^1]: https://github.com/stefan-hoeck/idris2-refined/