diff --git a/README.md b/README.md
index f1aa3ba..de3bb28 100644
--- a/README.md
+++ b/README.md
@@ -86,4 +86,4 @@ Feedback and ideas welcome!
 
 - [Official announcement thread on the squeak-dev mailing list](http://forum.world.st/ANN-Squeak-Inbox-Talk-bringing-squeak-dev-into-your-image-td5130575.html) ([mirror on lists.squeakfoundation.org](http://lists.squeakfoundation.org/pipermail/squeak-dev/2021-July/216008.html))
 - [Official announcement of HyperKitty release on squeak-dev](https://lists.squeakfoundation.org/archives/list/squeak-dev@lists.squeakfoundation.org/thread/KTIGYGMSC2IK45HIFMKY44WZVPE4BKEU/)
-- [Christoph Thiede, and Patrick Rein. *Squeak by Example. 5.3.1 Edition.* 2021.](https://wiki.squeak.org/squeak/6546)
+- [Christoph Thiede and Patrick Rein. *Squeak by Example. 6.0 Edition.* Lulu, 2023. ISBN 978-1-4476-2948-1.](https://www.lulu.com/shop/patrick-rein-and-christoph-thiede/squeak-by-example-60/paperback/product-8vr2j2.html)