CREATE TABLE Courses (author_id VARCHAR(255), course_name VARCHAR(255)); CREATE TABLE Course_Authors_and_Tutors (address_line_1 VARCHAR(255), author_id VARCHAR(255))
Find the addresses of the course authors who teach the course with name "operating system" or "data structure".
    
SQL: 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"