Update README.md

Author: lemire

README.md

@@ -164,3 +164,9 @@ a filter from more than one goroutine, you should
 provide synchronization. Typically this is done by using channels (in Go style; so there is only ever one owner),
 or by using `sync.Mutex` to serialize operations. Exceptionally, you may access the same filter from different
 goroutines if you never modify the content of the filter.
+
+
+## Further reading
+
+<p>Mastering Programming: From Testing to Performance in Go</p>
+<div><a href="https://www.amazon.com/dp/B0FMPGSWR5"><img style="margin-left: auto; margin-right: auto;" src="https://m.media-amazon.com/images/I/61feneHS7kL._SL1499_.jpg" alt="" width="250px" /></a></div>