use pubs
go

set statistics io on
--set showplan on
go
SELECT * FROM authors
WHERE au_id IN 
	(SELECT au_id FROM titleauthor
	WHERE title_id IN 
		(SELECT title_id FROM titles
		WHERE type = 'business'))
go
SELECT DISTINCT a.* 
FROM authors a, titleauthor ta,  titles t
WHERE a.au_id = ta.au_id AND ta.title_id =t.title_id 
	AND type = 'business'
