doc update

Author: mtumilowicz

README.md

@@ -4,7 +4,8 @@
 Functional programming patterns in java.
 
 _Reference_: https://www.youtube.com/watch?v=YnzisJh-ZNI  
-_Reference_: https://www.youtube.com/watch?v=e4MT_OguDKg
+_Reference_: https://www.youtube.com/watch?v=e4MT_OguDKg  
+_Reference_: https://www.youtube.com/watch?v=ePXnCezwRuw  
 _Reference_: https://www.amazon.com/Modern-Java-Action-functional-programming/dp/1617293563
 
 # introduction