Update VectorSearch.md

Author: mingxiw

demos/guru_scripts/docker/tutorial/4.x/VectorSearch.md

@@ -25,7 +25,8 @@ This GSQL tutorial contains
   - [Global and Local Schema Change](#global-and-local-schema-change)
   - [Vector Data Loading](#vector-data-loading)
   - [Python Integration](#python-integration)
-- [Support](#support) 
+- [Support](#support)
+- [Reference](#reference) 
 
 # Setup Environment 
 
@@ -1063,3 +1064,9 @@ Or, study our product document at
 
 [Go back to top](#top)
 
+# Reference
+TigerVector: Supporting Vector Search in Graph Databases for Advanced RAGs [https://arxiv.org/abs/2501.11216]
+
+
+[Go back to top](#top)
+