diff --git a/sandbox/index.mdwn b/sandbox/index.mdwn
index 6c5739e59..9902ebbbc 100644
--- a/sandbox/index.mdwn
+++ b/sandbox/index.mdwn
@@ -252,3 +252,8 @@ Screen annotation:
 
 - <http://impressive.sourceforge.net/>
 - Evgeny Morozov talks about The Syllabus <https://www.listennotes.com/podcasts/this-machine-kills/134-morozov-watch-ft-evgeny-8St5pZjbeAM/>
+
+---
+
+- [[sTeX: Semantic Markup for LaTeX · KWARC|https://kwarc.info/systems/sTeX/]]
+    * [[M. Kohlhase (2008) Using LaTeX as a semantic markup format. Mathematics in Computer Science 2 (2), pp. 279–304|https://kwarc.info/kohlhase/papers/mcs08-stex.pdf]]