GITBOOK-870: No subject

Author: dgafka

quick-start-php-ddd-cqrs-event-sourcing/asynchronous-php.md

@@ -16,7 +16,7 @@ Step by step refactor from synchronous code to full resilient asynchronous code
 
 [Read more about Asynchronous in PHP and Ecotone](https://blog.ecotone.tech/asynchronous-php/)
 
-[Building Reactive Message-Driven Systems in PHP](broken-reference)
+[Building Reactive Message-Driven Systems in PHP](https://blog.ecotone.tech/building-reactive-message-driven-systems-in-php/)
 
 ## Code Example