diff --git a/readme.md b/readme.md
index 0de5886..994a124 100644
--- a/readme.md
+++ b/readme.md
@@ -222,8 +222,8 @@ Implementations of the Lightning Network Protocol
 ### Books
 
 - [Mastering the Lightning Network (LN)](https://github.com/lnbook/lnbook)
-- [Mastering Bitcoin, 2nd Edition](http://shop.oreilly.com/product/0636920049524.do)
-- [Bitcoin and Lightning Network on Raspberry Pi](https://www.apress.com/gp/book/9781484255216)
+- [Mastering Bitcoin, 3rd Edition](https://www.oreilly.com/library/view/mastering-bitcoin-3rd/9781098150082/?_gl=1*jxo2l7*_ga*OTIxNDU5MjUxLjE3NDU0MDYxOTM.*_ga_092EL089CH*MTc0NTQwNjE5My4xLjEuMTc0NTQwNjIyNS4yOC4wLjA.)
+- [Bitcoin and Lightning Network on Raspberry Pi][def]
 
 ## Community
 
@@ -261,3 +261,6 @@ Contributions welcome! Read the [contribution guidelines](contributing.md) first
 
 To the extent possible under law, the author has waived all copyright and
 related or neighboring rights to this work.
+
+
+[def]: https://www.apress.com/gp/book/9781484255216
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