diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index ae319c7..e4cf3e4 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -19,5 +19,5 @@ again.
 
 All submissions, including submissions by project members, require review. We
 use GitHub pull requests for this purpose. Consult
-[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
+[GitHub Help](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/about-pull-requests) for more
 information on using pull requests.
diff --git a/enn/colabs/enn_demo.ipynb b/enn/colabs/enn_demo.ipynb
index b5db969..5acccde 100644
--- a/enn/colabs/enn_demo.ipynb
+++ b/enn/colabs/enn_demo.ipynb
@@ -104,25 +104,19 @@
     "\n",
     "import warnings\n",
     "\n",
-    "warnings.filterwarnings('ignore')\n",
-    "\n",
-    "\n",
+    "warnings.filterwarnings('ignore')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
     "#@title Development imports\n",
-    "from typing import Callable, NamedTuple\n",
-    "\n",
-    "import numpy as np\n",
-    "import pandas as pd\n",
-    "import plotnine as gg\n",
-    "\n",
     "from acme.utils.loggers.terminal import TerminalLogger\n",
     "import dataclasses\n",
-    "import chex\n",
-    "import haiku as hk\n",
-    "import jax\n",
-    "import jax.numpy as jnp\n",
-    "import optax\n",
-    "import tensorflow as tf\n",
-    "import tensorflow_datasets as tfds"
+    "import optax"
    ]
   },
   {
@@ -135,15 +129,11 @@
    "outputs": [],
    "source": [
     "#@title ENN imports\n",
-    "import enn\n",
     "from enn import losses\n",
     "from enn import networks\n",
     "from enn import supervised\n",
-    "from enn import base\n",
     "from enn import data_noise\n",
-    "from enn import utils\n",
-    "from enn.supervised import classification_data\n",
-    "from enn.supervised import regression_data\n"
+    "from enn.supervised import classification_data, regression_data"
    ]
   },
   {
@@ -173,6 +163,7 @@
     "  learning_rate: float = 1e-3\n",
     "  noise_std: float = 0.1\n",
     "\n",
+    "\n",
     "FLAGS = Config()"
    ]
   },
@@ -202,7 +193,7 @@
     "# Logger\n",
     "logger = TerminalLogger('supervised_regression')\n",
     "\n",
-    "# Create Ensemble ENN with a prior network \n",
+    "# Create Ensemble ENN with a prior network\n",
     "enn = networks.MLPEnsembleMatchedPrior(\n",
     "    output_sizes=[50, 50, 1],\n",
     "    dummy_input=next(dataset).x,\n",
@@ -211,11 +202,11 @@
     "    seed=FLAGS.seed,\n",
     ")\n",
     "\n",
-    "# L2 loss on perturbed outputs \n",
+    "# L2 loss on perturbed outputs\n",
     "noise_fn = data_noise.GaussianTargetNoise(enn, FLAGS.noise_std, FLAGS.seed)\n",
     "single_loss = losses.add_data_noise(losses.L2Loss(), noise_fn)\n",
     "loss_fn = losses.average_single_index_loss(single_loss, FLAGS.num_index_samples)\n",
-    " \n",
+    "\n",
     "# Optimizer\n",
     "optimizer = optax.adam(FLAGS.learning_rate)\n",
     "\n",
diff --git a/enn/colabs/epinet_demo.ipynb b/enn/colabs/epinet_demo.ipynb
index ed1ff08..c47723d 100644
--- a/enn/colabs/epinet_demo.ipynb
+++ b/enn/colabs/epinet_demo.ipynb
@@ -78,26 +78,20 @@
     "\n",
     "import warnings\n",
     "\n",
-    "warnings.filterwarnings('ignore')\n",
-    "\n",
-    "\n",
+    "warnings.filterwarnings('ignore')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
     "#@title Development imports\n",
-    "from typing import Callable, NamedTuple\n",
-    "\n",
-    "import numpy as np\n",
     "import pandas as pd\n",
     "import plotnine as gg\n",
-    "\n",
-    "from acme.utils.loggers.terminal import TerminalLogger\n",
-    "import dataclasses\n",
-    "import chex\n",
-    "import haiku as hk\n",
     "import jax\n",
-    "import jax.numpy as jnp\n",
-    "import optax\n",
-    "import dill\n",
-    "import tensorflow as tf\n",
-    "import tensorflow_datasets as tfds"
+    "import dill"
    ]
   },
   {
@@ -110,12 +104,8 @@
    "outputs": [],
    "source": [
     "#@title ENN imports\n",
-    "import enn\n",
-    "from enn import datasets\n",
-    "from enn.checkpoints import base as checkpoint_base\n",
     "from enn.networks.epinet import base as epinet_base\n",
     "from enn.checkpoints import utils\n",
-    "from enn.checkpoints import imagenet\n",
     "from enn.checkpoints import catalog\n",
     "from enn import metrics as enn_metrics"
    ]