The adult editions started releasing in 2004, replacing the original adult editions. The adult editions feature simplistic designs to appeal to an older audience and were published in hardcover and paperback. In 2015 Bloomsbury released a new set of adult editions.
Harry Potter Adult Editions 2004 — Harry Potter Database
UK First Edition Harry Potter Prisoner Of Azkaban JK, 49% OFF
Harry Potter Books — Harry Potter Database
Harry Potter Set: Adult Edition: Rowling, J. K.: 9781408898659: : Books
harry potter adult edition products for sale
Why Are Harry Potter First Editions So Expensive?, 51% OFF
Harry Potter and the Chamber of Secrets: Adult Edition )] [Author: J. K. Rowling] [Jul-2004]: unknown author: 8601417244791: : Books
Why Are Harry Potter First Editions So Expensive?, 51% OFF
Harry Potter and the Chamber of Secrets: Adult Edition )] [Author: J. K. Rowling] [Jul-2004]: unknown author: 8601417244791: : Books