diff --git a/_posts/13-04-01-Books.md b/_posts/13-04-01-Books.md
index 0bd5558..5f6d10f 100644
--- a/_posts/13-04-01-Books.md
+++ b/_posts/13-04-01-Books.md
@@ -22,3 +22,8 @@ available as a book completely for free
 
 * [Modernizing Legacy Applications In PHP](https://leanpub.com/mlaphp) - Get 
 your code under control in a series of small, specific steps
+* [Building Secure PHP Apps](https://leanpub.com/buildingsecurephpapps) - Learn the security basics that a senior developer usually acquires over years of experience, all condensed down into one quick and easy handbook
+* [The Grumpy Programmer's Guide To Building Testable PHP Applications](https://leanpub.com/grumpy-testing) - Learning to write testable doesn't have to suck
+* [Build APIs You Won't Hate](https://leanpub.com/build-apis-you-wont-hate) - Everyone and their dog wants an API, so you should probably learn how to build them
+* [Scaling PHP](https://leanpub.com/scalingphp) - Stop playing sysadmin and get back to coding
+* [Signaling PHP](https://leanpub.com/signalingphp) - PCNLT signals are a great help when writing PHP scripts that run from the command line.