diff --git a/README.md b/README.md
index 1d68fdf6bb..5a68fa5ba7 100644
--- a/README.md
+++ b/README.md
@@ -5,15 +5,17 @@ Discuss and ask questions in our Discussions: https://github.com/graphql-java/gr
 This is a [GraphQL](https://github.com/graphql/graphql-spec) Java implementation.
 
 [![Build](https://github.com/graphql-java/graphql-java/actions/workflows/master.yml/badge.svg)](https://github.com/graphql-java/graphql-java/actions/workflows/master.yml)
-[![Latest Release](https://img.shields.io/maven-central/v/com.graphql-java/graphql-java?versionPrefix=20.)](https://maven-badges.herokuapp.com/maven-central/com.graphql-java/graphql-java/)
+[![Latest Release](https://img.shields.io/maven-central/v/com.graphql-java/graphql-java?versionPrefix=21.)](https://maven-badges.herokuapp.com/maven-central/com.graphql-java/graphql-java/)
 [![Latest Snapshot](https://img.shields.io/maven-central/v/com.graphql-java/graphql-java?label=maven-central%20snapshot&versionPrefix=0)](https://maven-badges.herokuapp.com/maven-central/com.graphql-java/graphql-java/)
 [![MIT licensed](https://img.shields.io/badge/license-MIT-green)](https://github.com/graphql-java/graphql-java/blob/master/LICENSE.md)
 
 ### Documentation
 
-We have a tutorial for beginners: [Getting started with GraphQL Java and Spring Boot](https://www.graphql-java.com/tutorials/getting-started-with-spring-boot/)
+See our tutorial for beginners: [Getting started with GraphQL Java and Spring Boot](https://www.graphql-java.com/tutorials/getting-started-with-spring-boot/)
 
-For details how to use `graphql-java` please look at the documentation: https://www.graphql-java.com/documentation/getting-started
+For further details, please see the documentation: https://www.graphql-java.com/documentation/getting-started
+
+If you're looking to learn more, we (the maintainers) have written a book! [GraphQL with Java and Spring](https://leanpub.com/graphql-java) includes everything you need to know to build a production ready GraphQL service. The book is available on [Leanpub](https://leanpub.com/graphql-java) and [Amazon](https://www.amazon.com/GraphQL-Java-Spring-Andreas-Marek-ebook/dp/B0C96ZYWPF/).
 
 Please take a look at our [list of releases](https://github.com/graphql-java/graphql-java/releases) if you want to learn more about new releases and the changelog.