Database: book_press
Question: Which authors publish books in both "MM" and "LT" series? Give me the author names.
SQL:
SELECT t1.name FROM author AS t1 JOIN book AS t2 ON t1.author_id  =  t2.author_id WHERE t2.book_series  =  'MM' INTERSECT SELECT t1.name FROM author AS t1 JOIN book AS t2 ON t1.author_id  =  t2.author_id WHERE t2.book_series  =  'LT'