Update README.md

Author: dominicpereira92

README.md

@@ -20,6 +20,8 @@ This easy-to-read book is packed with real-world examples, and with its fast-pac
 
 ![Amazon reviews](https://github.com/PacktPublishing/R-Data-Structures-and-Algorithms/blob/master/Amazon.png)
 
+You can purchase this book at Amazon [R Data Structures and Algorithms](https://www.amazon.com/dp/1786465159)
+
 ## Instructions and Navigations
 All of the code is organized into folders. Each folder starts with a number followed by the application name. For example, Chapter02.