diff --git a/graphs_trees/bst/bst_challenge.ipynb b/graphs_trees/bst/bst_challenge.ipynb
index 2dc27d7..6284d44 100644
--- a/graphs_trees/bst/bst_challenge.ipynb
+++ b/graphs_trees/bst/bst_challenge.ipynb
@@ -63,7 +63,7 @@
    "source": [
     "## Algorithm\n",
     "\n",
-    "Refer to the [solution notebook](https://github.com/donnemartin/interactive-coding-challenges/graphs_trees/bst/bst_solution.ipynb).  If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
+    "Refer to the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/bst/bst_solution.ipynb).  If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
    ]
   },
   {
@@ -183,7 +183,7 @@
    "source": [
     "## Solution Notebook\n",
     "\n",
-    "Review the [solution notebook](https://github.com/donnemartin/interactive-coding-challenges/graphs_trees/bst/bst_solution.ipynb) for a discussion on algorithms and code solutions."
+    "Review the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/bst/bst_solution.ipynb) for a discussion on algorithms and code solutions."
    ]
   }
  ],