diff --git a/README.md b/README.md
index 21c28d3..f687752 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,7 @@ Course material:
 
 1. [Intro_CL.pdf](https://marcbezem.github.io/CL-PC22/Intro_CL.pdf)
 1. [Site_CL.pdf](https://marcbezem.github.io/CL-PC22/Site_CL.pdf)
+1. [Skolem_CL.pdf](https://marcbezem.github.io/CL-PC22/Site_CL.pdf)
 1. LABresources (directory)
 
 SWI Prolog: https://www.swi-prolog.org/