diff --git a/Appendix-B---References.md b/Appendix-B---References.md
index ac83831..a6e8fd0 100644
--- a/Appendix-B---References.md
+++ b/Appendix-B---References.md
@@ -18,6 +18,7 @@ If you would like to submit a resource link to be added to this list, please pos
 * [Firefox Telemetry Dashboards](https://telemetry.mozilla.org/) - **h**ttps://telemetry.mozilla.org/
 * [Mozilla Developer Network](https://developer.mozilla.org/) - **h**ttps://developer.mozilla.org/
    * [Firefox Docs](https://developer.mozilla.org/Firefox) - **h**ttps://developer.mozilla.org/Firefox
+   * [Preferences Guide](https://developer.mozilla.org/en-US/docs/Mozilla/Preferences/A_brief_guide_to_Mozilla_preferences) - **h**ttps://developer.mozilla.org/docs/Mozilla/Preferences/A_brief_guide_to_Mozilla_preferences
    * [Web APIs](https://developer.mozilla.org/docs/Web/API) - **h**ttps://developer.mozilla.org/docs/Web/API
 * [Mozilla Security Advisories](https://www.mozilla.org/security/advisories/) - **h**ttps://www.mozilla.org/security/advisories/
 * [Mozilla Security Blog](https://blog.mozilla.org/security/) - **h**ttps://blog.mozilla.org/security/