Add References section to CloudNative PostgreSQL Guide

Guide-Database.md

@@ -6,6 +6,7 @@
 - [Installation](#installation)
 - [Backup](#backup)
 - [Recovery](#recovery)
+- [References](#references)
 
 ## Overview
 
@@ -262,3 +263,13 @@ Once recovery is complete, follow these steps to return to normal operation:
 
 1. Change `spec.values.mode` from `recovery` to `standalone`
 2. Change `spec.values.backups.enabled` to `true`
+
+## References
+
+### Official Documentation
+- [CloudNative-PG Official Documentation](https://cloudnative-pg.io/docs/)
+- [CloudNative-PG GitHub Repository](https://github.com/cloudnative-pg/cloudnative-pg)
+
+### Helm Chart Examples
+- [Cluster Helm Chart Values](https://github.com/cloudnative-pg/charts/blob/main/charts/cluster/values.yaml)
+- [Cluster Helm Chart Examples](https://github.com/cloudnative-pg/charts/tree/main/charts/cluster/examples)