12 books • 8 series
Doctor Who: The Ninth Doctor Adventures 2.3 - Hidden Depths (Doctor Who - The Ninth Doctor Adventures, #2.3)
Doctor Who: The Fourth Doctor Adventures Series 11 - Volume 2: The Nine (Doctor Who: The Fourth Doctor Adventures Series 11, #2)
Doctor Who The Monthly Adventures #272 The Grey Man of the Mountain (Doctor Who The Monthly Adventures, #272)