Abstract Classes and Abstract Methods in C#.NET?

http://www.programcall.com/27/csnet/abstract-classes-and-abstract-methods-in-csnet.aspx

http://www.dotnetperls.com/abstract

http://www.c-sharpcorner.com/uploadfile/annathurai/abstract-class-in-c-sharp/

http://www.dotnet-tricks.com/Tutorial/csharp/E0K2011113-A-Deep-Dive-into-C

http://www.onlinebuff.com/article_abstract-class-and-abstract-method-with-an-example-using-c_7.html

http://www.codeproject.com/Articles/6118/All-about-abstract-classes