diff --git a/Docs/source/theory/picsar_theory.rst b/Docs/source/theory/picsar_theory.rst
index 14573abd8f1..389d8afe71e 100644
--- a/Docs/source/theory/picsar_theory.rst
+++ b/Docs/source/theory/picsar_theory.rst
@@ -692,4 +692,4 @@ filter with large stencil, resulting in more favorable scaling with the number
 of computational cores for parallel calculations.
 
 .. bibliography::
-    :keyprefix: pt-
\ No newline at end of file
+    :keyprefix: pt-