There are three novels on Greg's reading table: Money, Ulysses, and Emma. On his next trip, he can choose to take some or none, but not all, of these novels. In the braces below, list all the possible sets of novels that Greg can take. Write each set in your list in roster form. If there is more than one set in your list, separate them with commas. If you need the empty set in your list, use the symbol e.