diff --git a/Docs/source/refs.bib b/Docs/source/refs.bib
index e3978a805..0137c25cd 100644
--- a/Docs/source/refs.bib
+++ b/Docs/source/refs.bib
@@ -635,6 +635,7 @@ @article{rock2
 year = {2001},
 volume = {90},
 pages = {1-18},
+}
 
 @misc{autodiff,
     author = {Leal, Allan M. M.},