diff --git a/free-programming-books.md b/free-programming-books.md
index 3c94b6a0872765eae55f8593e8f2f71c8ec494f0..e5625b6a807136ebcf6aef3bad25e6c6495bfa65 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -337,6 +337,7 @@
 * [The Art of Computer Programming](http://www.cs.utsa.edu/~wagner/knuth/) - Donald Knuth (fascicles, mostly volume 4)
 * [The Design of Approximation Algorithms](http://www.designofapproxalgs.com/book.pdf) (PDF)
 * [The Great Tree List Recursion Problem](http://cslibrary.stanford.edu/109/TreeListRecursion.pdf) (PDF)
+* [The Kademlia Protocol Succinctly](https://www.syncfusion.com/ebooks/kademlia_protocol_succinctly) - Marc Clifton
 * [Think Complexity](http://greenteapress.com/complexity/) (PDF)
 
 
@@ -455,6 +456,7 @@
 * [Gaussian Processes for Machine Learning](http://www.gaussianprocess.org/gpml/)
 * [Information Theory, Inference, and Learning Algorithms](http://www.inference.phy.cam.ac.uk/itila/)
 * [Interpretable Machine Learning](https://christophm.github.io/interpretable-ml-book/) - Christoph Molnar
+* [Introduction to CNTK Succinctly](https://www.syncfusion.com/ebooks/cntk_succinctly) - James McCaffrey
 * [Introduction to Machine Learning](http://arxiv.org/abs/0904.3664v1) - Amnon Shashua
 * [Keras Succinctly](https://www.syncfusion.com/ebooks/keras-succinctly) - James McCaffrey
 * [Learn Tensorflow](https://bitbucket.org/hrojas/learn-tensorflow) - Jupyter Notebooks
@@ -560,6 +562,7 @@
 * [Google Maps API Succinctly](https://www.syncfusion.com/ebooks/google_maps_api_succinctly) - Mark Lewin
 * [Hacknot: Essays on Software Development](http://www.lulu.com/shop/ed-johnson/hacknot-essays-on-software-development/ebook/product-17544641.html) - Ed Johnson
 * [High-Performance Scientific Computing](https://andreask.cs.illinois.edu/Teaching/HPCFall2012) (class lectures and slides)
+* [HoloLens Succinctly](https://www.syncfusion.com/ebooks/hololens_succinctly) - Lars Klint
 * [How Computers Work](http://www.fastchip.net/howcomputerswork/p1.html) - R. Young
 * [How to Become a Programmer](http://softwarebyrob.wpengine.netdna-cdn.com/assets/Software_by_Rob%20_How_to_Become_a%20_Programmer_1.0.pdf) (PDF)
 * [How to Think Like a Computer Scientist](http://openbookproject.net/thinkcs/) - Peter Wentworth, Jeffrey Elkner, Allen B. Downey, and Chris Meyers
@@ -1000,7 +1003,8 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Mastering Xamarin UI Development, Second Edition](https://www.packtpub.com/free-ebooks/mastering-xamarin-ui-development-second-edition) - Steven F. Daniel (Packt account *required*)
 * [Object Oriented Programming using C#](http://bookboon.com/en/object-oriented-programming-using-c-sharp-ebook) - Simon Kendal, Bookboon. (email address *requested*, not required)
 * [Threading in C#](http://www.albahari.com/threading/)
-* [Xamarin.Forms Succinctly, Syncfusion](https://www.syncfusion.com/ebooks/xamarin-forms-succinctly) (PDF, Kindle) (email address requested, not required)
+* [Xamarin.Forms for macOS Succinctly](https://www.syncfusion.com/ebooks/xamarin_forms_for_mac_os_succinctly) - Alessandro Del Sole
+* [Xamarin.Forms Succinctly](https://www.syncfusion.com/ebooks/xamarin-forms-succinctly) - Alessandro Del Sole
 
 
 ### C++
@@ -1402,6 +1406,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Pro HTML5 Programming](https://web.archive.org/web/20181215200026/http://apress.jensimmons.com/v5/pro-html5-programming/ch0.html) - Jen Simmons, Chris O'Connor, Dylan Wooters, Peter Lubbers
 * [Scalable and Modular Architecture for CSS](https://web.archive.org/web/20191116073929/http://smacss.com/) - Jonathan Snook
 * [Understanding Flexbox: Everything you need to know](https://ohansemmanuel.github.io/uf_download.html) - Ohans Emmanuel
+* [W3.CSS Succinctly](https://www.syncfusion.com/ebooks/w3_css_succinctly) - Joseph D. Booth
 * [Web Audio API](http://chimera.labs.oreilly.com/books/1234000001552) - Boris Smus
 
 
@@ -1924,8 +1929,10 @@ Kerridge (PDF) (email address *requested*, not required)
 
 ### .NET Framework
 
+* [Akka.NET Succinctly](https://www.syncfusion.com/ebooks/akka_net_succinctly) - Zoran Maksimovic
 * [Clean Code .NET](https://github.com/thangchung/clean-code-dotnet)
 * [Entity Framework](http://weblogs.asp.net/zeeshanhirani/my-christmas-present-to-the-entity-framework-community)
+* [Entity Framework Core Succinctly](https://www.syncfusion.com/ebooks/entity_frame_work_core_succinctly) - Ricardo Peres
 * [Game Creation with XNA](https://en.wikibooks.org/wiki/Game_Creation_with_XNA) - Wikibooks
 * [Getting the Most from LINQPad Succinctly](https://www.syncfusion.com/ebooks/getting-the-most-from-linqpad-succinctly) - José Roberto Olivas Mendoza
 * [MonoGame Succinctly](https://www.syncfusion.com/ebooks/monogame_succinctly) - Jim Perry