Tell me Julio's address
select address_line_1 from course_authors_and_tutors where personal_name = "Julio"
Tell me the number of courses that he teaches.
select count(*) from course_authors_and_tutors as t1 join courses as t2 on t1.author_id = t2.author_id where personal_name = "Julio"
Tell me the addresses and author IDs of the course authors that teach at least two courses.
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