C# Language Specification
The C# Language Specification is the definitive source for C# syntax and usage. This spec contains detailed information about all aspects of the language, including many points that the documentation for Visual C# doesn't cover.
You can download this spec from the Microsoft Download Center. If you've installed Visual Studio 2013, you can also find the spec on your computer in the Program Files (x86)/Microsoft Visual Studio 12.0/VC#/Specifications/1033 folder. However, installations of Visual Studio Express 2013 don't include this file.