Which course authors teach two or more courses? Give me their addresses and author IDs.
SELECT T1.address_line_1 ,  T2.author_id FROM Course_Authors_and_Tutors AS T1 JOIN Courses AS T2 ON T1.author_id  =  T2.author_id GROUP BY T2.author_id HAVING Count(*)  >=  2
course authors teach two or more courses refers to HAVING COUNT(*) >= 2; addresses refers to address_line_1; author IDs refers to author_id;