diff --git a/free-programming-books.md b/free-programming-books.md
index f118fd117..68a535dfc 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -275,6 +275,7 @@
 * [GPU Gems](https://developer.nvidia.com/gpugems/GPUGems/gpugems_pref01.html)
 * [Graphics Programming Black Book](http://www.gamedev.net/page/resources/_/technical/graphics-programming-and-theory/graphics-programming-black-book-r1698) - Michael Abrash
 * [Introduction to Modern OpenGL](https://open.gl)
+* [Introduction to TouchDesigner 099](https://leanpub.com/introductiontotouchdesigner/) *(Leanpub account or valid email requested)*
 * [Learn OpenGL](http://learnopengl.com) - Joey de Vries
 * [Learning Modern 3D Graphics Programming](https://web.archive.org/web/20150225192611/http://www.arcsynthesis.org/gltut/index.html) - Jason L. McKesson (draft)
 * [OpenGL](http://www.songho.ca/opengl/index.html) - Concepts and illustrations.
@@ -996,6 +997,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [C# Notes](https://goalkicker.com/CSharpBook) (PDF)
 * [C# Notes for Professionals](http://books.goalkicker.com/CSharpBook/) - Compiled from StackOverflow documentation (3.x)
 * [C# Programming](https://en.wikibooks.org/wiki/C_Sharp_Programming) - Wikibooks
+* [C# Tips](https://leanpub.com/cstips) - Jason Roberts *(Leanpub account or valid email requested)*
 * [C# Yellow Book](http://www.csharpcourse.com) (intro to programming)
 * [Creating Mobile Apps with Xamarin.Forms C#](https://developer.xamarin.com/guides/xamarin-forms/creating-mobile-apps-xamarin-forms/)
 * [Daily Design Patterns](https://web.archive.org/web/20170930132000/https://www.exceptionnotfound.net/downloads/dailydesignpattern.pdf) - Matthew P Jones (PDF)
@@ -2460,6 +2462,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Learning Scalaz](http://eed3si9n.com/learning-scalaz/)
 * [Pro Scala: Monadic Design Patterns for the Web](https://github.com/leithaus/XTrace/tree/monadic/src/main/book/content/)
 * [Programming in Scala, First Edition](http://www.artima.com/pins1ed/) - by M. Odersky, L. Spoon, B. Venners
+* [Pure functional HTTP APIs in Scala](https://leanpub.com/pfhais/read) - Jens Grassel
 * [PythonToScala](https://wrobstory.gitbooks.io/python-to-scala/content/) - Rob Story
 * [S-99: Ninety-Nine Scala Problems](http://aperiodic.net/phil/scala/s-99/) - Phil! Gold
 * [Scala & Design Patterns: Exploring Language Expressivity](http://www.scala-lang.org/old/sites/default/files/FrederikThesis.pdf) - Fredrik Skeel Løkke (PDF)