public Task <PageList <Author> > GetPageAsync(ResourcesParameters pageParameters)
        {
            IQueryable <Author> source = DbContext.Set <Author>();

            if (!string.IsNullOrEmpty(pageParameters.AuthorName))
            {
                source = source.Where(m => m.Name.Contains(pageParameters.AuthorName));
            }
            var orderSource = source.OrderBy(pageParameters.SortBy);

            return(PageList <Author> .CreatePageLsit(orderSource, pageParameters.PageIndex, pageParameters.PageSize));
        }