From e9ef7ba6d81db68a90b17864b3bd153a86012bed Mon Sep 17 00:00:00 2001
From: Johan Wigert <45201794+jwigert@users.noreply.github.com>
Date: Sun, 18 Oct 2020 20:56:10 +0200
Subject: [PATCH] Update free-programming-books-de.md (#4389)

---
 free-programming-books-de.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/free-programming-books-de.md b/free-programming-books-de.md
index f730ebe20..fdfde4fee 100644
--- a/free-programming-books-de.md
+++ b/free-programming-books-de.md
@@ -34,6 +34,7 @@
 
 ### ABAP
 
+* [Einstieg in ABAP](http://openbook.rheinwerk-verlag.de/einstieg_in_abap/) - Karl-Heinz Kühnhauser, Thorsten Franz
 * [SAP Code Style Guides - Clean ABAP](https://github.com/SAP/styleguides/blob/master/clean-abap/CleanABAP_de.md)