diff --git a/doc/cups.md.license b/doc/cups.md.license
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+++ b/doc/cups.md.license
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+/*
+ * SPDX-FileCopyrightText: 2022 Software Ingenieur Begerad <swingbe.de>
+ *
+ * SPDX-License-Identifier: CC0-1.0
+ */
diff --git a/doc/postgres.md.license b/doc/postgres.md.license
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+/*
+ * SPDX-FileCopyrightText: 2022 Software Ingenieur Begerad <swingbe.de>
+ *
+ * SPDX-License-Identifier: CC0-1.0
+ */
diff --git a/doc/ssh-tunnel.md b/doc/ssh-tunnel.md
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+# Connect to remote Postgre SQL Database using SSH Tunnel
+
+```
+ssh -L <local port>:<local host address>:<remote port> -p <SSH port of remote SSH server> <user at remote server>@<host name of remote server>
+```
+
+## Links
+
+[Connect to PostgreSQL using an SSH tunnel](https://www.kevssite.com/connect-to-postgresql-using-an-ssh-tunnel/)
diff --git a/doc/ssh-tunnel.md.license b/doc/ssh-tunnel.md.license
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+++ b/doc/ssh-tunnel.md.license
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+/*
+ * SPDX-FileCopyrightText: 2022 Software Ingenieur Begerad <swingbe.de>
+ *
+ * SPDX-License-Identifier: CC0-1.0
+ */
diff --git a/doc/static-gtfs-manager.md.license b/doc/static-gtfs-manager.md.license
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+++ b/doc/static-gtfs-manager.md.license
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+/*
+ * SPDX-FileCopyrightText: 2022 Software Ingenieur Begerad <swingbe.de>
+ *
+ * SPDX-License-Identifier: CC0-1.0
+ */