private static void GetTitleWithPrice(string val)
        {
            libs      = new LibraryIndexController();
            unvalLibs = new LibraryIndexUnvalidatedController();
            Console.Clear();
            Console.WriteLine("Please insert the price (Between 0 and 2599:");
            double price = Convert.ToDouble(Console.ReadLine());

            Console.Clear();
            if (val == "v")
            {
                libs.GetTitleWithPrice(price);
            }
            else
            {
                unvalLibs.GetTitleWithPrice(price);
            }
        }