using System.Xml.XPath;
class Program {
   static void Main() {
      XPathDocument document = new XPathDocument(@"C:\books.xml");
      XPathNavigator navigator = document.CreateNavigator();
      XPathNodeIterator iterator = 
         navigator.Select(@"/bookstore/book/author/first-name");
      while( iterator.MoveNext() )
         System.Console.WriteLine("<" + iterator.Current.Name + ">" + 
                                  iterator.Current.Value);
   }
}