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README.md

@@ -894,7 +894,7 @@ Various resources, such as books, websites and articles, for improving your PHP
 * [Head First Design Patterns](http://www.headfirstlabs.com/books/hfdp/) - A book that expains software design patterns.
 * [Pro Git](https://git-scm.com/book/en/v2) - A book about Git by Scott Chacon and Ben Straub.
 * [The Linux Command Line](http://linuxcommand.org/tlcl.php) - A book about the Linux command line by William Shotts.
-* [The Tangled Web — Securing Web Applications](http://www.amazon.com/Tangled-Web-Securing-Modern-Applications/dp/1593273886) - A book about securing web applications by Michal Zalewski.
+* [The Tangled Web — Securing Web Applications](https://www.amazon.com/Tangled-Web-Securing-Modern-Applications/dp/1593273886) - A book about securing web applications by Michal Zalewski.
 * [Understanding Computation](http://computationbook.com) - A book about computation theory by Tom Stuart.
 * [Vagrant Cookbook](https://leanpub.com/vagrantcookbook) - A book about creating Vagrant environments by Erika Heidi.