How to get the First, second and third Monday of the month b

Question

I want to get the first, second and third Monday of the Month between two dates. I can get the first Monday of the month but not between two day. Below is my code. Any help will be appreciated.

class Program
   {
       public class BusinessWeekDays
       {
           public DateTime Tuesday;
           public DateTime Monday;
       }


       static void Main(string[] args)
       {
           var StartDate = DateTime.Parse("04/25/2019");
           var SeriesEndDate = DateTime.Parse("09/30/2019");

           for (int mth = 1; mth <= 12; mth++)
           {
               DateTime dt = new DateTime(2010, mth, 1);
               while (dt.DayOfWeek != DayOfWeek.Monday)
               {
                   dt = dt.AddDays(1);
               }
               Console.WriteLine(dt.ToLongDateString());
           }
           Console.ReadLine();
           //for (var i = StartDate; i < SeriesEndDate; i = i.AddMonths(Monthly))
           //{

           //    months.Add(new BusinessWeekDays { Tuesday = dt, Monday = dt.AddDays(7) });

           //    Console.WriteLine(months);
           //}
       }