diff --git a/Notebooks/Chap19/19_4_Temporal_Difference_Methods.ipynb b/Notebooks/Chap19/19_4_Temporal_Difference_Methods.ipynb
index f325c14..7135aec 100644
--- a/Notebooks/Chap19/19_4_Temporal_Difference_Methods.ipynb
+++ b/Notebooks/Chap19/19_4_Temporal_Difference_Methods.ipynb
@@ -31,7 +31,7 @@
       "source": [
         "# **Notebook 19.4: Temporal difference methods**\n",
         "\n",
-        "This notebook investigates temporal differnece methods for  tabular reinforcement learning as described in section 19.3.3 of the book\n",
+        "This notebook investigates temporal difference methods for  tabular reinforcement learning as described in section 19.3.3 of the book\n",
         "\n",
         "Work through the cells below, running each cell in turn. In various places you will see the words \"TO DO\". Follow the instructions at these places and make predictions about what is going to happen or write code to complete the functions.\n",
         "\n",