diff --git a/README.md b/README.md
index 7910dbe..9748a16 100644
--- a/README.md
+++ b/README.md
@@ -192,7 +192,9 @@ If you're not sure how to contribute, please follow **[this handy tutorial](http
 6. [OpenSSH Manual](https://www.openssh.com/manual.html)
 7. [Principle of Least Privilege](https://techcommunity.microsoft.com/t5/azure-sql/security-the-principle-of-least-privilege-polp/ba-p/2067390)
 8. [Introduction to Linux](http://ftp.wayne.edu/ldp/en/Intro-Linux/Intro-Linux.pdf) - Hands on guide to learn Linux.
-9. [Learn Shell](https://www.learnshell.org/) - learn programming with Unix/Linux shell interpreters.
+9. [Learn Shell](https://www.learnshell.org/) - Learn programming with Unix/Linux shell interpreters.
+10. [Linux Upskill Challenge](https://linuxupskillchallenge.org/) - Learn the Linux terminal with a free and open source 21 day course
+
 ## Other interesting stuff <a name="misc"></a>
 
 1. [E Foundation](https://e.foundation)