From this post I can bundle a single CDN file. So How to bundle many CDN files in one line ? Do I only need a list of strings and repeat this line for each item?
public static void RegisterBundles(BundleCollection bundles){
bundles.UseCdn = true;
var jqueryCdnPath = "http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.7.1.min.js";
bundles.Add(new ScriptBundle("~/bundles/jquery",
jqueryCdnPath).Include("~/Scripts/jquery-{version}.js"));
}