public void createBook(string title, string ISBN, string pages, string publicationInfo, string signId, List <string> authors) { BookRepository bookManagerObj = new BookRepository(); Book newBook = new Book(); newBook.Title = title; newBook.ISBN = ISBN; newBook.pages = Convert.ToInt16(pages); newBook.publicationinfo = publicationInfo; newBook.SignId = Convert.ToInt32(signId); AuthorRepository authorGrabber = new AuthorRepository(); List <AUTHOR> authorList = new List <AUTHOR>(); foreach (var author in authors) { var grabbedAuthor = authorGrabber.ReadUninclude(Convert.ToInt32(author)); authorList.Add(grabbedAuthor); } newBook.Author = Mapper.Map <List <Author> >(authorList); bookManagerObj.CreateNew(Mapper.Map <BOOK>(newBook)); }