NDLのJsonデータをC#シリアライザでデシリアイズする

gistfile1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Threading;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Globalization;

namespace CSharpTest
{

    [DataContract]
    class NDLJsonData
    {
        [DataMember]
        public string link;
        [DataMember]
        public NDLJsonDataIdentifier identifier; 
        [DataMember]
        public NDLJsonDataTitle[] title;
        [DataMember]
        public string[] volume;
        [DataMember]
        public NDLJsonDataTitle[] seriesTitle;
        [DataMember]
        public NDLJsonDataCreator[] creator;
        [DataMember]
        public NDLJsonDataCreator[] dc_creator;
        [DataMember]
        public NDLJsonDataPublisher[] publisher;
        [DataMember]
        public string[] date;
        [DataMember]
        public string[] issued;
        [DataMember]
        public NDLJsonDataSubject subject;
        [DataMember]
        public string price;
        [DataMember]
        public string[] extent;
        [DataMember]
        public string[] materialType;
    }
    [DataContract]
    class NDLJsonDataTitle
    {
        [DataMember]
        public string value;
        [DataMember]
        public string transcription;
    }
    [DataContract]
    class NDLJsonDataIdentifier
    {
        [DataMember]
        public string[] JPNO;
        [DataMember]
        public string[] ISBN;
    }
    [DataContract]
    class NDLJsonDataCreator
    {
        [DataMember]
        public string name;
        [DataMember]
        public string transcription;
    }
    [DataContract]
    class NDLJsonDataPublisher
    {
        [DataMember]
        public string name;
        [DataMember]
        public string location;
    }
    [DataContract]
    class NDLJsonDataSubject
    {
        [DataMember]
        public string[] NDC9;
    }

    class Program
    {
        static void Main(string[] args)
        {
            var url = "http://iss.ndl.go.jp/books/R100000002-I000003057246-00.json";
            var req = WebRequest.CreateHttp(url);
            var stream = req.GetResponse().GetResponseStream();
            var serializer = new DataContractJsonSerializer(typeof(NDLJsonData));
            var data = (NDLJsonData)serializer.ReadObject(stream);
            var list = new List<KeyValuePair<string, string>>();
            list.Add(new KeyValuePair<string, string>("タイトル", data.title[0].value));
            list.Add(new KeyValuePair<string, string>("著者", data.dc_creator[0].name));
            list.Add(new KeyValuePair<string, string>("著者標目", data.creator[0].name));
            list.Add(new KeyValuePair<string, string>("シリーズ名", data.seriesTitle[0].value));
            list.Add(new KeyValuePair<string, string>("出版社", data.publisher[0].name));
            list.Add(new KeyValuePair<string, string>("出版年", data.date[0]));
            list.Add(new KeyValuePair<string, string>("巻次", data.volume[0]));
            Console.WriteLine(data.title[0].value+" "+data.volume[0]);
            Console.WriteLine("----------------------------------------");
            foreach(var i in list)
            {
                Console.WriteLine(i.Key+" : "+i.Value);
            }
        }
    }
}