Yes, There’s a Bookstore at King of Prussia Mall: Barnes & Noble

Barnes & Noble operates a full-size store on the upper level, near Nordstrom. It carries books, magazines, toys, games, and has a café. Hours: typically 10am–9pm (Mon–Sat), 11am–6pm (Sun)—verify for holidays.

It’s the only dedicated bookstore in the mall. For used/rare books, try nearby shops in Wayne or online.