diff --git a/free-programming-books-id.md b/free-programming-books-id.md
index 2cf6421c5..28f6caaf5 100644
--- a/free-programming-books-id.md
+++ b/free-programming-books-id.md
@@ -112,6 +112,7 @@
 
 * [Membuat Bot Telegram dengan PHP](https://www.slideshare.net/HasanudinHS/ebook-i-membuat-bot-telegram-dengan-php) - Hasanudin H Syafaat - (PDF)
 * [Pemrograman Berbasis Objek Modern dengan PHP](https://arsiteknologi.com/wp-content/uploads/Pemrograman_Berbasis_Objek_Modern_dengan_PHP_Google_Play_Book.pdf) - Muhamad Surya Iksanudin (PDF)
+* [Pemrograman Berorientasi Objek Dengan PHP5](https://endangcahyapermana.files.wordpress.com/2016/03/belajar-singkat-pemrograman-berorientasi-objek-dengan-php5.pdf) - Gerry Sabar (PDF)
 * [Pemrograman Web dengan PHP dan MySQL](http://achmatim.net/2009/04/15/buku-gratis-pemrograman-web-dengan-php-dan-mysql/)
 * [PHP: The Right Way Bahasa Indonesia](http://id.phptherightway.com/#site-header/)
 * [Tutorial Ebook PHP](http://www.ilmuwebsite.com/ebook-php-free-download)
diff --git a/free-programming-books.md b/free-programming-books.md
index 991f20793..bebca6dff 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -2596,6 +2596,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Learn Ruby on Rails as You Modify a Craigslist Clone](http://www.thinkful.com/learn/ruby-on-rails-tutorial/)
 * [Objects on Rails](https://web.archive.org/web/20190319201525/http://objectsonrails.com/) - Avdi Grimm
 * [Rails Girls Guides](http://guides.railsgirls.com)
+* [Ruby Notes for Professionals](https://books.goalkicker.com/RubyBook/) - Compiled from StackOverflow Documentation (PDF)
 * [Ruby on Rails 3.2 - Step by Step](http://www.xyzpub.com/en/ruby-on-rails/3.2/)
 * [Ruby on Rails 4.0 Guide](http://www.xyzpub.com/en/ruby-on-rails/4.0/)
 * [Ruby on Rails Guides](http://guides.rubyonrails.org)