diff --git a/15_hierarchical_modelling.ipynb b/15_hierarchical_modelling.ipynb
index 62c83fe..20a3134 100644
--- a/15_hierarchical_modelling.ipynb
+++ b/15_hierarchical_modelling.ipynb
@@ -57,8 +57,10 @@
         "The sampling order in this example follows the computational graph: \n",
         "\n",
         "$$\n",
-        "b \\to a \\to \\theta \\to y.\n",
-        "$$"
+        "\\begin{array}{c}\n",
+        "b\\\\ \\downarrow\\\\ a\\\\ \\downarrow\\\\ \\theta\\\\ \\downarrow\\\\ y\n",
+        "\\end{array}\n",
+        "$$\n"
       ]
     },
     {
@@ -381,7 +383,7 @@
     },
     {
       "cell_type": "code",
-      "execution_count": 11,
+      "execution_count": null,
       "metadata": {},
       "outputs": [
         {
@@ -460,11 +462,15 @@
         }
       ],
       "source": [
-        "df = pd.read_csv('data/sleepstudy.csv')\n",
+        "# To get the file using wget\n",
+        "# !wget -O sleepstudy.csv https://raw.githubusercontent.com/elizavetasemenova/prob-epi/main/data/sleepstudy.csv\n",
+        "# df = pd.read_csv('sleepstudy.csv')\n",
+        "# Drop the colum\n",
+        "# df = df.drop('Unnamed: 0', axis=1)\n",
+        "# df.head()\n",
         "\n",
-        "#!wget -O sleepstudy.csv https://github.com/elizavetasemenova/prob-epi/blob/main/data/sleepstudy.csv\n",
-        "#df = pd.read_csv('sleepstudy.csv', sep=\";\")\n",
         "\n",
+        "df = pd.read_csv('data/sleepstudy.csv')\n",
         "# Drop the column\n",
         "df = df.drop('Unnamed: 0', axis=1)\n",
         "df.head()"