diff --git a/pages/concepts.topology.md b/pages/concepts.topology.md
index ee9cef3..b019041 100644
--- a/pages/concepts.topology.md
+++ b/pages/concepts.topology.md
@@ -29,6 +29,7 @@ source: https://www.merriam-webster.com/dictionary/topology
 
 ```
 
+- https://www.quantamagazine.org/in-topology-when-are-two-shapes-the-same-20210928/
 
 - [[concepts.topography]]
 - [[fulldocs.mastodon.gis]]