diff --git a/README.md b/README.md
index 30a07ee..824069f 100644
--- a/README.md
+++ b/README.md
@@ -104,5 +104,6 @@ changes are applied.
   grep)
 
 ## Additional resources
+* [How to use the Firefox Browser Toolbox](https://developer.mozilla.org/en-US/docs/Tools/Browser_Toolbox)
 * [firefox-csshacks](https://github.com/MrOtherGuy/firefox-csshacks/)
 * [FirefoxCSS subreddit](https://www.reddit.com/r/FirefoxCSS/)