public IActionResult Publishers()
        {
            IEnumerable <PublisherViewModel> model = publisherRepository.GetAll().Select(s => new PublisherViewModel
            {
                PublisherId = s.PublisherId,
                Name        = $"{s.Name}",
                Region      = s.Region,
                Books       = publisherRepository.GetBooksByPublisherId(s.PublisherId),
            });

            return(View(model));
        }