Until
December 18, 2012 at 11:59pm PT, Microsoft Press are offering CLR via C#, 4th Edition as an e-book at $23.99 at
http://shop.oreilly.com/product/0790145353665.do?code=HDMSN"Dig deep and master the intricacies of the common language runtime, C#,
and .NET development. Led by programming expert Jeffrey Richter, a
longtime consultant to the Microsoft .NET team—you’ll gain pragmatic
insights for building robust, reliable, and responsive apps and
components."