using System;
using System.Collections.Generic;
using System.Linq;
 
class User
{
  public string Name { get; set; }
}
 
public class Test
{
  public static void Main()
  {
    var users = new List<User>
    {
      new User { Name = "John"   },
      new User { Name = "Katia"  },
      new User { Name = "Dmitry" },
      new User { Name = "James"  },
    };
 
    var names = new List<string> { "Dmitry", "Katia", "Vova" };
 
    List<User> res = (from u in users join n in names on u.Name equals n select u).ToList();
 
    foreach (var user in res)
      Console.WriteLine(user.Name);
  }
}

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