how to reference strong named assembly in my .aspx web page

Add a reference by copying the dependent DLLs into your
~/bin directory, or if the DLLs you need are in the GAC then you can use
the @assembly by specifying the assembly's fully qualified name:

<%@ Assembly Name="SomeAssemblyNameWithOutTheDLLExtension, Culture=neutral, Version=1.2.0.0, PublicKeyToken=38218fe715288aac" %>

The Version and PublicKeyToken you should gte from looking in the GAC (which
is c:\windows\assembly).