Database: aan_1
Question: Find the number of authors who did not publish any paper that is cited more than 50 times.
SQL:
SELECT count(*) FROM Author WHERE Author_id NOT IN ( SELECT T2.author_id FROM Citation AS T1 JOIN Author_list AS T2 ON T1.cited_paper_id  =  T2.paper_id GROUP BY T1.cited_paper_id HAVING count(DISTINCT T1.paper_id)  >  50)