A version of this Best Sellers report appears in the September 27, 2020 issue of The New York Times Book Review. Rankings on weekly lists reflect sales for the week ending September 12, 2020 .

Rankings reflect unit sales reported on a confidential basis by vendors offering a wide range of general interest titles published in the United States. Every week, thousands of diverse selling locations report their actual sales on hundreds of thousands of individual titles. The panel of reporting retailers is comprehensive and reflects sales in tens of thousands of stores of all sizes and demographics across the United States.

The book selling universe is comprised of well-established vendors as well as emerging ones. The sales venues for print books include national, regional and local chains representing tens of thousands of storefronts; many hundreds of independent book retailers; scores of online and multimedia entertainment retailers; supermarkets, university, gift and big-box department stores; and newsstands.

E-book rankings reflect sales from leading online vendors of e-books in a variety of popular e-reader formats and are included in our combined fiction, combined nonfiction, advice, children's series and monthly lists. Titles are included regardless of whether they are published in both print and electronic formats or just one format. In general, publisher credits for e-books are listed under the corporate publishing name instead of by publisher's division or imprint, unless by special request. Graphic book rankings include all print and digital formats. Adult, children's, young adult, fiction and nonfiction graphic books are eligible for inclusion on the graphic books and manga list. Audiobook rankings are created from sales of physical and digital audio products. Free-trial or low-cost audiobook sales are not eligible for inclusion. Publisher credits for audiobooks are listed under the audiobook publisher name.

The appearance of a ranked title reflects the fact that sales data from reporting vendors has been provided to The Times and has satisfied commonly accepted industry standards of universal identification (such as ISBN13 and EISBN13 codes). All identities, anecdotal, contextual, and other information about the retail sales of any title, as well as overall sales data, are provided with the expectation and assurance of confidentiality by every vendor and are protected by Non-Disclosure Agreements.

Sales are defined as completed transactions by vendors and individual end users during the period on or after the official publication date of a title. Institutional, special interest, group or bulk purchases, if and when they are included, are at the discretion of The New York Times Best-Seller List Desk editors based on standards for inclusion that encompass proprietary vetting and audit protocols, corroborative reporting and other statistical determinations. When included, such bulk purchases appear with a dagger (†).

Publishers and vendors of all ranked titles must conform in a timely fashion to The New York Times Best-Seller Lists requirement to allow for examination and independent corroboration of their reported sales for that week. Sales are statistically weighted to represent and accurately reflect all outlets proportionally nationwide. An asterisk (*) indicates that a book's sales are barely distinguishable from those of the book above.

Among the categories not actively tracked at this time are: perennial sellers, required classroom reading, textbooks, reference and test preparation guides, e-books available exclusively from a single vendor, journals, workbooks, calorie counters, shopping guides, periodicals and crossword puzzles.

The New York Times Best Sellers are compiled and archived by The Best-Seller Lists Desk of The New York Times News Department, and are separate from the Editorial, Culture, Advertising and Business sides of The New York Times Company.

If you are a book retailer interested in reporting your store's weekly sales to The New York Times Best-Seller Lists, send a request here.

Please direct other questions and feedback to nytbsl@nytimes.com.