diff --git a/README.md b/README.md
index 9b9c971..bd9c13a 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,8 @@ Version 3.0 goes together without glue so parts are replacable.
 Insert models use my 
 [Inserts Library](https://sancus.carpanet.net/sjc/inserts)
 
+Box parts rely on [BOSL](https://github.com/revarbat/BOSL)
+
 Modify parameters as you like, the default will give a pretty decent
 aproximation of the original that it is based on which will mount on 
 similar stands. Change dimensions and you are on your own. Not all