diff --git a/tree-structures.md b/tree-structures.md
index 2df761070..8274fde5c 100644
--- a/tree-structures.md
+++ b/tree-structures.md
@@ -1,4 +1,15 @@
 # tree structures
 
 - https://twitter.com/flancian/status/1375493771786326016
+  - [[pull]] [[tree-notation]]
+  - [[pull]] [[wittgenstein-protocol]]
+  - [[pull]] [[chess-hypothesis]]
 
+
+
+[//begin]: # "Autogenerated link references for markdown compatibility"
+[pull]: pull "Pull"
+[tree-notation]: tree-notation "tree notation"
+[wittgenstein-protocol]: wittgenstein-protocol "Wittgenstein Protocol"
+[chess-hypothesis]: chess-hypothesis "Chess hypothesis"
+[//end]: # "Autogenerated link references"
\ No newline at end of file