SELECT publisher FROM book_club WHERE YEAR  =  1989 INTERSECT SELECT publisher FROM book_club WHERE YEAR  =  1990
Show publishers with a book published in 1989 and a book in 1990.
SELECT publisher FROM book_club WHERE YEAR = 1989 INTERSECT SELECT publisher FROM book_club WHERE YEAR = 1990
select publisher from book_club where year = value intersect select publisher from book_club where year = value
Show publishers with a book published in 1989 and a book in 1990 .