static void Main(string[] args) { List <Student> students = GetStudents(); University university = new University("CH.U.I."); foreach (var stud in students) { university.AddStudent(stud); } Internship internship = new Internship("Interlink"); foreach (var stud in university.Students) { internship.SetStudent(stud); } Console.WriteLine("List of internship's students:"); Console.WriteLine(internship.GetStudents()); Console.ReadKey(); }