Thanks you for reply. But i am trying it, it still do not works.
private void RegisterCSSInclude(Control target)
{
Type rsType = this.GetType();
string csslink = @"<link rel="stylesheet" type="text/css" href="" + <br mode="hold" /> Page.ClientScript.GetWebResourceUrl(rsType, "Lib.Style.base.css") + "" />";
LiteralControl include = new LiteralControl(csslink);
this.Page.Header.Controls.Add(include);
}