Claim: Avatar: The Last Airbender referred to their episodes as "books".
Evidence: Avatar : The Last Airbender -LRB- Avatar : The Legend of Aang in some regions -RRB- is an American animated television series that aired for three seasons -LRB- referred to as `` books '' in each episode 's title card -RRB- on Nickelodeon from 2005 to 2008.