In the books published by US publishers, which book has the highest royalty? List these books in the descending order of royalty.
US publisher refers publisher in the US where country = 'USA';
SELECT T1.title FROM titles AS T1 INNER JOIN publishers AS T2 ON T1.pub_id = T2.pub_id INNER JOIN roysched AS T3 ON T1.title_id = T3.title_id WHERE T2.country = 'USA' ORDER BY T1.royalty DESC