diff --git a/SFR.ipynb b/SFR.ipynb
index 4a1c789..ecfe1e3 100644
--- a/SFR.ipynb
+++ b/SFR.ipynb
@@ -13,7 +13,8 @@
     "# A Sodium Fast Reactor geometry \n",
     "This notebook can be used as a template for modeling Sodium fast reactors.\n",
     "\n",
-    "SOURCE:\n",
+    "SOURCES:\n",
+    "A. Facchini, V. Giusti, R. Ciolini, K. Tucek, D. Thomas, E. D'Agata, \"Detailed Neutornics Study of the Power Evolution for the European Sodium Fast Reactor During a Positive Insertion of Reactivity,\" Nuc. Eng. Design  313 1-9 (2017)\n",
     "A. Ponomarev, A. Bednarova, K. Mikityuk, \"New Sodium Fast Reactor Neutronics Benchmark,\" PHYSOR 2018"
    ]
   },