*[Fundamentals of Computer Programming with C#](http://www.introprogramming.info/english-intro-csharp-book/read-online/) - Svetlin Nakov
*[High level asynchronous programming with Reactive Extensions](https://github.com/petroemil/Rx.Book) - Emil Petro
*[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*)
*[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/)
*[Introduction to PowerShell for Unix People](https://www.gitbook.com/book/devopscollective/a-unix-person-s-guide-to-powershell/details)(PDF, ePub, HTML)
*[Layman’s Guide to PowerShell 2.0 remoting](http://www.ravichaganti.com//blog/wp-content/uploads/2010/12/A%20layman's%20guide%20to%20PowerShell%202.0%20remoting-v2.pdf)(PDF)
*[Learn PowerShell Core 6.0](https://www.packtpub.com/free-ebooks/learn-powershell-core-60) - David das Neves, Jan-Hendrik Peters (Packt account *required*)
*[Learn PowerShell in Y Minutes](https://learnxinyminutes.com/docs/powershell/)