// @nuget: HtmlAgilityPack

​

using System;

using System.Xml;

using HtmlAgilityPack;

public class Program

{

    public static void Main()

    {

        var html = @"https://www.vinabook.com/";

​

        HtmlWeb web = new HtmlWeb();

​

        var htmlDoc = web.Load(html);

​

        var node = htmlDoc.DocumentNode.SelectSingleNode("//div[@class='mainbox-body']/div[@class='box-info-wrapper']/div[@class='span-4']/form/div[@class='box-info-book float-left']/div[@class='pic-book']/a[@href]");

​

        Console.WriteLine("Node Name: " + node.GetAttributeValue("href", ""));

    }

}

​