diff --git a/pages/UpEnd.md b/pages/UpEnd.md
index 8b848d8..00bff95 100644
--- a/pages/UpEnd.md
+++ b/pages/UpEnd.md
@@ -120,6 +120,8 @@ Idea s [[filesystem]]em jakozto databazi s metadaty:
 <https://www.haiku-os.org/docs/userguide/en/workshop-filetypes+attributes.html>
 
 # Information enters, is processed
+<https://blog.owulveryck.info/2020/11/13/ontology-graphs-and-turtles-part-i.html>
+
 ![[mapping_language.png]]
 
 <details>