diff --git a/book/_static/attribution.css b/book/_static/attribution.css
new file mode 100644
index 0000000..45aa569
--- /dev/null
+++ b/book/_static/attribution.css
@@ -0,0 +1,4 @@
+/* Attribution */
+div.attribution > .admonition-title::after {
+    content: "\f10d";
+}