await async from ms

http://msdn.microsoft.com/ru-ru/library/hh191443.aspxhttp://msdn.microsoft.com/ru-ru/magazine/jj991977.aspxhttp://www.dotnetperls.com/async

http://blog.stephencleary.com/2012/02/async-and-await.html

http://www.sansys.net/2013/05/asynchronous-programming-in-csharp-using-async-and-await.html

https://www.simple-talk.com/dotnet/.net-framework/the-.net-4.5-asyncawait-feature-in-promise-and-practice/

http://blogs.msdn.com/b/bclteam/archive/2012/10/22/using-async-await-without-net-framework-4-5.aspx