diff --git a/README.md b/README.md
index 72149e1..6d9673f 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,9 @@
+## Programmable command-line calculator using reverse polish notation
+
 [![Actions](https://github.com/tlinden/rpnc/actions/workflows/ci.yaml/badge.svg)](https://github.com/tlinden/rpnc/actions)
 [![License](https://img.shields.io/badge/license-GPL-blue.svg)](https://github.com/tlinden/rpnc/blob/master/LICENSE)
 [![Go Report Card](https://goreportcard.com/badge/github.com/tlinden/rpnc)](https://goreportcard.com/report/github.com/tlinden/rpnc) 
 
-## Reverse Polish Notation Calculator for the commandline
-
 This is a small commandline calculator which takes its input in
 [reverse polish notation](https://en.wikipedia.org/wiki/Reverse_Polish_notation)
 form.
@@ -69,6 +69,8 @@ DEBUG(012):      push to stack: 200.00
 = 200
 ```
 
+For a very good explanation how reverse polish notation and the stack works [watch this video by Prof. Brailsford](https://youtu.be/7ha78yWRDlE?si=9MCp59jAAG8fXavP)
+
 ## Usage
 
 Basically   you  enter   numbers  followed   by  an   operator  or   a