Jane has a somewhat different view from Bob as follows: Her emphasis is on authors and books. She is aware of the following facts. Each book is written by one or more authors, whose social security number, name, and address are maintained. One author can write one or more books. For each book written by a particular author$($s$),$ a sum of money is paid as royalty. This amount varies for each book as well as for each author. The ISBN number, field, and type are information required for a book