diff --git a/themes/writeonly/layouts/_default/single.html b/themes/writeonly/layouts/_default/single.html
index 6e49474..b8f1e8d 100644
--- a/themes/writeonly/layouts/_default/single.html
+++ b/themes/writeonly/layouts/_default/single.html
@@ -12,6 +12,7 @@
         </div>
         <div class="markdown-content py-2">
           {{ .Content }}
+          {{ partial "shared/post-isbn" . }}
         </div>
       </div>
     </div>
diff --git a/themes/writeonly/layouts/partials/shared/post-isbn.html b/themes/writeonly/layouts/partials/shared/post-isbn.html
new file mode 100644
index 0000000..a867e6e
--- /dev/null
+++ b/themes/writeonly/layouts/partials/shared/post-isbn.html
@@ -0,0 +1,8 @@
+<div class="text-center text-muted mb-1">
+  {{ with .Params.ISBN }}
+    <span class="d-inline-flex align-items-center small mx-2">
+      <i class="fa-solid fa-book"></i>
+      <a href="https://search.worldcat.org/search?q={{ . }}&offset=1"> ISBN {{ . }}</a>
+    </span>
+  {{ end }}
+</div>