doc update

mtumilowicz · mtumilowicz · commit 8b5a475b155c · 2019-01-07T22:10:52.000+01:00
diff --git a/README.md b/README.md
@@ -1 +1,2 @@
 # java11-concurrency-lock-execute-around-method-pattern
+_Reference_: https://www.amazon.com/gp/product/1937785467

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`1`	`1`	`# java11-concurrency-lock-execute-around-method-pattern`
	`2`	`+_Reference_: https://www.amazon.com/gp/product/1937785467`