diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 731e16a..35e0606 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -21,15 +21,18 @@ some ideas on how to contribute.
 .
 ├── CODE_OF_CONDUCT.md
 ├── CONTRIBUTING.md
+├── LICENSE.txt
 ├── Makefile
 ├── README.md
+├── cheatsheets
+│   └── ...
 ├── index.html             # Published HTML.
 ├── requirements-dev.txt   # Dependencies for development.
 ├── requirements.txt       # Dependencies.
 ├── scripts                # Shell scripts for development, testing and deployment.
 │   └── ...
 ├── tests-as-linear.ipynb  # Main notebook.
-└── tests_as_linear        # Python source code
+└── tests_as_linear        # Supporting Python source code.
     ├── __init__.py
     ├── plots.py           # Functions for large plots in main notebook.
     └── utils.py           # Utility functions used in main notebook.
diff --git a/Makefile b/Makefile
index 4c8e41a..241f8f8 100644
--- a/Makefile
+++ b/Makefile
@@ -41,7 +41,7 @@ test: clean  # Run test scripts.
 check: clean lint test  # Alias for `make clean lint test`.
 
 black:  # Format code in-place with black.
-	black *.py --target-version=py36
+	black tests_as_linear/ --target-version=py36
 
 publish:  # Run notebook in-place and generate HTML files.
 	jupyter nbconvert --to notebook --inplace --execute tests-as-linear.ipynb
diff --git a/README.md b/README.md
index efe5d49..fe32036 100644
--- a/README.md
+++ b/README.md
@@ -26,14 +26,11 @@ please refer to the [original appendices
 upstream](https://github.com/lindeloev/tests-as-linear/tree/master/simulations)
 for the simulations.
 
-<div class="alert alert-warning">
-    Finally, certain statistical functions and tests are supported by neither
-    <code>statsmodels</code> or <code>scipy</code>, the two statistical Python
-    libraries used in this port. R code with no simple Python equivalent (mainly
-    in parts 6 and 7, <i>Three or more means</i> and <i>Proportions: Chi-square
-    is a log-linear model</i>) has not been ported. Such code has been noted in
-    yellow warning boxes such as this one.
-</div>
+Finally, certain statistical functions and tests are supported by neither
+`statsmodels` or `scipy`, the two statistical Python libraries used in this
+port. R code with no simple Python equivalent (mainly in sections 6 and 7,
+"Three or more means" and "Proportions: Chi-square is a log-linear model") has
+not been ported. Such code has been noted in yellow warning boxes.
 
 ## Contributing
 
diff --git a/index.html b/index.html
index 48a7ff4..9509c82 100644
--- a/index.html
+++ b/index.html
@@ -13298,10 +13298,10 @@ <h1 id="2-Python-environment">2 Python environment<a class="anchor-link" href="#
 <span class="kn">import</span> <span class="nn">scipy</span>
 <span class="kn">import</span> <span class="nn">statsmodels.api</span> <span class="k">as</span> <span class="nn">sm</span>
 <span class="kn">import</span> <span class="nn">statsmodels.formula.api</span> <span class="k">as</span> <span class="nn">smf</span>
+<span class="c1"># See GitHub repo for supporting Python code.</span>
 <span class="kn">from</span> <span class="nn">tests_as_linear</span> <span class="k">import</span> <span class="n">plots</span><span class="p">,</span> <span class="n">utils</span>
 
 <span class="n">np</span><span class="o">.</span><span class="n">random</span><span class="o">.</span><span class="n">seed</span><span class="p">(</span><span class="mi">1618</span><span class="p">)</span>
-<span class="n">plt</span><span class="o">.</span><span class="n">style</span><span class="o">.</span><span class="n">use</span><span class="p">(</span><span class="s1">&#39;seaborn-whitegrid&#39;</span><span class="p">)</span>
 </pre></div>
 
     </div>
diff --git a/tests-as-linear.ipynb b/tests-as-linear.ipynb
index aa8ee88..37d321d 100644
--- a/tests-as-linear.ipynb
+++ b/tests-as-linear.ipynb
@@ -144,10 +144,10 @@
     "import scipy\n",
     "import statsmodels.api as sm\n",
     "import statsmodels.formula.api as smf\n",
+    "# See GitHub repo for supporting Python code.\n",
     "from tests_as_linear import plots, utils\n",
     "\n",
-    "np.random.seed(1618)\n",
-    "plt.style.use('seaborn-whitegrid')"
+    "np.random.seed(1618)"
    ]
   },
   {
diff --git a/tests_as_linear/plots.py b/tests_as_linear/plots.py
index 53a3082..63915cb 100644
--- a/tests_as_linear/plots.py
+++ b/tests_as_linear/plots.py
@@ -4,6 +4,8 @@
 import matplotlib.pyplot as plt
 from .utils import signed_rank, format_decimals_factory
 
+plt.style.use("seaborn-whitegrid")
+
 
 def linear_regression_plot():
     # Construct data as a pd.DataFrame