Update README.md

Author: Carl-Firle

README.md

@@ -2,7 +2,7 @@
 As a medical doctor and researcher, I learned to conduct data analysis using Mathematica \[version 13.1\]. This tool is amazing.
 For a friend called Rebekka, I give an introduction to the program in German.
 
-Therefor, you find 4 Mathematica-Notebook-Files \(.nb\). I included audio-files to explain the functioning.
-Just download the .nb-files (and audio files), open them and start listening to my voice.
+Therefor, you find 4 Mathematica-Notebook-Files \(.nb\). I included audio files to explain the functioning.
+Just download the .nb-files and the xlsx.file (and audio files), open them with Wolfram Mathematica and start listening to my voice.
 
 Enjoy the discovery!