diff --git a/layouts/partials/cite_book.html b/layouts/partials/cite_book.html
index 0f61165..d8ed6f7 100644
--- a/layouts/partials/cite_book.html
+++ b/layouts/partials/cite_book.html
@@ -23,6 +23,6 @@
 {{ with .pages }}pp. {{ . }}.{{ end }}
 
 {{/* ISBN */}}
-{{ with .isbn }}ISBN {{ . }}.{{ end }}
+{{ with .isbn }}ISBN <a target="_blank" href="https://en.wikipedia.org/wiki/Special:BookSources/{{ . }}">{{ . }}</a>.{{ end }}
 
 </div>