-- Database schema
| book_club : book_club_id [ INT ] primary_key , Year [ INT ] , Author_or_Editor [ TEXT ] , Book_Title [ TEXT ] , Publisher [ TEXT ] , Category [ TEXT ] , Result [ TEXT ] | movie : movie_id [ INT ] primary_key , Title [ TEXT ] , Year [ INT ] , Director [ TEXT ] , Budget_million [ INT ] , Gross_worldwide [ INT ] | culture_company : Company_name [ TEXT ] primary_key , Type [ TEXT ] , Incorporated_in [ TEXT ] , Group_Equity_Shareholding [ INT ] , book_club_id [ TEXT ] culture_company.book_club_id = book_club.book_club_id , movie_id [ TEXT ] culture_company.movie_id = movie.movie_id |
-- -- What are all the different book publishers?

SELECT DISTINCT publisher FROM book_club;