diff --git a/doc/erko_howto_tools.txt b/doc/erko_howto_tools.txt
index 4146bec45c38f9d6b98fb7bbdf4bb8d3183ffb00..7a09338cec4bb7e6b18a3fc1eaba713b5f8c8b96 100755
--- a/doc/erko_howto_tools.txt
+++ b/doc/erko_howto_tools.txt
@@ -150,6 +150,8 @@ gen_doc.py --fpga unb2b_minimal  # result in build/unb2b/args/unb2b_minimal/doc/
 * GIT references
 *******************************************************************************
 
+https://ohshitgit.com/
+
 difftool ?
 mergetool ?