Rankings reflect sales at almost 4,000 bookstores plus wholesalers serving 50,000 other retailers (gift shops, department stores, newsstands, supermarkets), statistically weighted to represent all such outlets nationwide.

The numbers are statistically weighted to represent sales in all such outlets nationwide.

Rankings reflect sales figures, for the week ending May 10, at 3,985 bookstores plus wholesalers serving 60,000 other retailers, statistically weighted to represent sales in all such outlets nationwide.

Rankings reflect sales, for the week ended May 6, at almost 4,000 bookstores plus wholesalers serving 50,000 other retailers, statistically weighted to represent all such outlets nationwide.

The universe of print book dealers is well established, and sales of print titles are statistically weighted to represent all outlets nationwide.

Rankings reflect sales figures, for the week ending March 5, at 3,050 bookstores and wholesalers serving 28,000 other retailers (gift shops, department stores, newsstands, supermarkets), statistically weighted to represent sales in all such outlets nationwide.