Get all Descendants by name in CSharp

using System;//from w  w w . j  a v  a  2  s.  com
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XDocument xDocument = new XDocument(
          new XElement("Books",
          new XElement("Book",
          new XAttribute("type", "Author"),
          new XElement("FirstName", "A"),
          new XElement("LastName", "B")),
          new XElement("Book",
          new XAttribute("type", "Author"),
          new XElement("FirstName", "C"),
          new XElement("LastName", "D"))));
        Console.WriteLine(xDocument);
        IEnumerable<XElement> elements = xDocument.Descendants("Book");
        foreach (XElement element in elements) {
            Console.WriteLine("Element: {0} : value = {1}",element.Name, element.Value);
        }
    }
}