@@ -458,6 +458,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
*[Introduction to Rx](http://www.introtorx.com)
*[Learn C# in Y Minutes](https://learnxinyminutes.com/docs/csharp/)
*[Mastering Xamarin UI Development, Second Edition](https://www.packtpub.com/free-ebooks/mastering-xamarin-ui-development-second-edition) - Steven F. Daniel (Packt account *required*)
*[.NET Book Zero](http://www.charlespetzold.com/dotnet) - Charles Petzold (PDF, XPS)
*[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 for macOS Succinctly](https://www.syncfusion.com/ebooks/xamarin_forms_for_mac_os_succinctly) - Alessandro Del Sole
