diff --git a/README.md b/README.md
index 20d8071..a0dd195 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,7 @@ Pull requests on interesting tools/projects/resources are welcome.
 
 * [Try Git](https://try.github.io/) - learn Git in 15 minutes with pseudo-terminal interface
 * [Atlassian Git Tutorial](https://www.atlassian.com/git/tutorials/) - comprehensive tutorial on Git
+* [Use gitk to understand git](https://lostechies.com/joshuaflanagan/2010/09/03/use-gitk-to-understand-git/) - all important Git terms (commit, commit SHA, branch, merge, rebase) explained using gitk
 * [Learn Version Control with Git](https://www.git-tower.com/learn/) - freemium ebook from fournova Software (makers for Tower), associated with paid video course
 * [Pro Git](https://git-scm.com/book/) - free Git book (CC BY-NC-SA 3.0)
 * [The Git Community Book](https://schacon.github.io/gitbook/) - book built by dozens of people in the Git community