doc update

Author: mtumilowicz

README.md

@@ -5,7 +5,8 @@
 _Reference_: [Out-of-the-box Reactive Streams with Java 9](https://www.youtube.com/watch?v=COgktgJmP_k)  
 _Reference_: https://github.com/rucek/reactive-streams-java9  
 _Reference_: https://github.com/reactive-streams/reactive-streams-jvm  
-_Reference_: https://docs.oracle.com/javase/9/docs/api/java/util/concurrent/Flow.html
+_Reference_: https://docs.oracle.com/javase/9/docs/api/java/util/concurrent/Flow.html  
+_Reference_: https://blog.softwaremill.com/how-not-to-use-reactive-streams-in-java-9-7a39ea9c2cb3
 
 ## preface
 The main goal of this project is to explore basic features of