SELECT T1.address_line_1 FROM Course_Authors_and_Tutors AS T1 JOIN Courses AS T2 ON T1.author_id  =  T2.author_id WHERE T2.course_name  =  "operating system" OR T2.course_name  =  "data structure"
What are the addresses of the course authors who teach either "operating system" or "data structure" course.
SELECT T1.address_line_1 FROM Course_Authors_and_Tutors AS T1 JOIN Courses AS T2 ON T1.author_id = T2.author_id WHERE T2.course_name = `` operating system '' OR T2.course_name = `` data structure ''
select t1 . address_line_1 from course_authors_and_tutors as t1 join courses as t2 on t1 . author_id = t2 . author_id where t2 . course_name = value or t2 . course_name = value
What are the addresses of the course authors who teach either `` operating system '' or `` data structure '' course .