Database: book_press
Question: Find the name of authors who publish their books in both "MM" and "LT" series.
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'