How many papers are there?
select count(*) from papers
What are all the institutions?
select * from inst
How many papers are published by "Tokohu University"?
select count(distinct t1.title) from papers as t1 join authorship as t2 on t1.paperid = t2.paperid join inst as t3 on t2.instid = t3.instid where t3.name = "Tokohu University"