diff --git a/books/free-programming-books-langs.md b/books/free-programming-books-langs.md
index 3ea6c41b..1b615e06 100644
--- a/books/free-programming-books-langs.md
+++ b/books/free-programming-books-langs.md
@@ -898,6 +898,8 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [A beginner's guide to HTML&CSS](http://learn.shayhowe.com/html-css/)
 * [A free guide to learn HTML and CSS](http://marksheet.io)
 * [Adaptive Web Design](http://adaptivewebdesign.info/1st-edition/) - Aaron Gustafson
+* [Airbnb CSS / Sass Styleguide](https://github.com/airbnb/css) - Airbnb
+* [Airbnb CSS-in-JavaScript Style Guide](https://airbnb.io/javascript/css-in-javascript/) - Airbnb
 * [An advanced guide to HTML&CSS](http://learn.shayhowe.com/advanced-html-css/)
 * [Atomic Design](https://atomicdesign.bradfrost.com) - Brad Frost
 * [Canvassing](https://web.archive.org/web/20160505010319/http://learnjs.io/canvassing/read/)
@@ -1081,6 +1083,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 
 ### JavaScript
 
+* [Airbnb JavaScript Style Guide() {](https://airbnb.io/javascript/) - Airbnb (HTML)
 * [Basic JavaScript for the impatient programmer](http://www.2ality.com/2013/06/basic-javascript.html) - Dr. Axel Rauschmayer (HTML)
 * [Book of Modern Frontend Tooling](https://github.com/tooling/book-of-modern-frontend-tooling) - Various (HTML)
 * [Building Front-End Web Apps with Plain JavaScript](https://web-engineering.info/JsFrontendApp-Book) - Gerd Wagner (HTML,PDF)
@@ -1274,6 +1277,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 
 #### React
 
+* [Airbnb React/JSX Style Guide](https://airbnb.io/javascript/react/) - Airbnb
 * [Full-Stack React Projects](https://www.packtpub.com/free-ebooks/full-stack-react-projects) - Shama Hoque (Packt account *required*)
 * [Hacking with React](http://www.hackingwithreact.com)
 * [How To Code in React.js](https://www.digitalocean.com/community/books/how-to-code-in-react-js-ebook) - Joe Morgan
@@ -2066,6 +2070,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [Ruby Notes for Professionals](https://goalkicker.com/RubyBook/) - Compiled from StackOverflow Documentation (PDF)
 * [Ruby one-liners cookbook](https://learnbyexample.github.io/learn_ruby_oneliners/) - Sundeep Agarwal
 * [Ruby Programming](http://www.linuxtopia.org/online_books/programming_books/ruby_tutorial/)
+* [Ruby Style Guide](https://github.com/airbnb/ruby) - Airbnb
 * [Ruby User's Guide](https://ruby-doc.org/docs/ruby-doc-bundle/UsersGuide/rg/index.html)
 * [Ruby Web Dev: The Other Way](https://leanpub.com/rwdtow/read) - Yevhen Kuzminov
 * [Rubyfu](https://rubyfu.net)