You would need the following:
CREATE PROCEDURE au_info (lastname varchar(40), firstname varchar(20))
RETURNING varhcar(40), varchar(20), varchar(30), varchar(50);
DEFINE lnameout varchar(40);
DEFINE fnameout varchar(20);
DEFINE titleout varchar(30);
DEFINE pubnameout varchar(50);
FOREACH
SELECT au_lname, au_fname, title, pub_name
INTO lnameout, fnameout, titleout, pubnameout
FROM authors a INNER JOIN titleauthor ta
ON a.au_id = ta.au_id INNER JOIN titles t
ON t.title_id = ta.title_id INNER JOIN publishers p
ON t.pub_id = p.pub_id
WHERE au_fname = firstname
AND au_lname = lastname
RETURN lnameout, fnameout, titleout, pubnameout WITH RESUME;
END FOREACH
END PROCEDURE
You will obviously need to change the field sizes for the titleout and pubnameout variables.
Hope this helps,
Jeremy