What are the names of all artists?
select distinct artist from artist
Which of them have released volumes?
select distinct t1.artist from artist as t1 join volume as t2 on t1.artist_id = t2.artist_id
Only show those whose volumes spent more than 2 weeks on top.
select distinct t1.artist from artist as t1 join volume as t2 on t1.artist_id = t2.artist_id where t2.weeks_on_top > 2
List the famous titles of these artists.
select t1.famous_title from artist as t1 join volume as t2 on t1.artist_id = t2.artist_id where t2.weeks_on_top > 2