diff --git a/benchmarks/.ipynb_checkpoints/cython_least_squares-checkpoint.ipynb b/benchmarks/.ipynb_checkpoints/cython_least_squares-checkpoint.ipynb
index 7c78e61..e28d5c5 100644
--- a/benchmarks/.ipynb_checkpoints/cython_least_squares-checkpoint.ipynb
+++ b/benchmarks/.ipynb_checkpoints/cython_least_squares-checkpoint.ipynb
@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:6fec0ff80302cd983b1b3ab4e6653aa12c291ed854c5efd69f28608d4f6af614"
+  "signature": "sha256:ed0de0773556cdc26dc372038810ad0e5322ec915298a90f2badf09740d856db"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -104,7 +104,9 @@
       "![](https://raw.githubusercontent.com/rasbt/python_reference/master/Images/least_squares_vertical.png)  \n",
       "![](https://raw.githubusercontent.com/rasbt/python_reference/master/Images/least_squares_perpendicular.png)  \n",
       "\n",
-      "Here, we will use the more common approach: minimizing the sum of the perpendicular offsets.\n"
+      "As Michael Burger summarizes it nicely in his article \"[Problems of Linear Least Square Regression - And Approaches to Handle Them](http://www.arsa-conf.com/archive/?vid=1&aid=2&kid=60101-220)\": \"the perpendicular offset method delivers a more precise result but is are more complicated to handle. Therefore normally the vertical offsets are used.\"  \n",
+      "Here, we will also use the method of computing the vertical offsets.\n",
+      "\n"
      ]
     },
     {
diff --git a/benchmarks/cython_least_squares.ipynb b/benchmarks/cython_least_squares.ipynb
index 7c78e61..e28d5c5 100644
--- a/benchmarks/cython_least_squares.ipynb
+++ b/benchmarks/cython_least_squares.ipynb
@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:6fec0ff80302cd983b1b3ab4e6653aa12c291ed854c5efd69f28608d4f6af614"
+  "signature": "sha256:ed0de0773556cdc26dc372038810ad0e5322ec915298a90f2badf09740d856db"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -104,7 +104,9 @@
       "![](https://raw.githubusercontent.com/rasbt/python_reference/master/Images/least_squares_vertical.png)  \n",
       "![](https://raw.githubusercontent.com/rasbt/python_reference/master/Images/least_squares_perpendicular.png)  \n",
       "\n",
-      "Here, we will use the more common approach: minimizing the sum of the perpendicular offsets.\n"
+      "As Michael Burger summarizes it nicely in his article \"[Problems of Linear Least Square Regression - And Approaches to Handle Them](http://www.arsa-conf.com/archive/?vid=1&aid=2&kid=60101-220)\": \"the perpendicular offset method delivers a more precise result but is are more complicated to handle. Therefore normally the vertical offsets are used.\"  \n",
+      "Here, we will also use the method of computing the vertical offsets.\n",
+      "\n"
      ]
     },
     {