如何查看标有extern和[MethodImplAttribute(MethodImplOptions.InternalCall)]方法的具体实现在哪儿

1：http://www.cnblogs.com/allenlooplee/archive/2004/12/14/76669.html

2：http://www.cnblogs.com/moshenks/archive/2011/01/20/1940673.html

3：SSCLI

    Shared Source Common Language Infrastructure 2.0 Release 下载：http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=4917