Write SQL query to solve given problem: In the papers classified as ML, how many cited butz01algorithmic?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT COUNT(T1.paper_id) FROM paper AS T1 INNER JOIN cites AS T2 ON T1.paper_id = T2.citing_paper_id WHERE T1.class_label = 'ML' AND T2.cited_paper_id = 'butz01algorithmic'