The Top Sales Person?

I am quite newbie, really grateful for some help how to create a sql sentence in Reporting Services that would return the best sales person from each shop.. The following returns all the sales persons from each shop

So how to select the top sales person from each shop?
SELECT TOP (10) shop.name, SUM(Cd.Price) AS Sales, Personal.Name AS Salesperson
FROM Purchase INNER JOIN
Personal
ON Purchase.Salesperson_id = Personal.Personal_id RIGHT OUTER JOIN shop
ON Personal.work_id = shop.shop_id FULL OUTER JOIN
Cd ON Purchase.Cd_id = Cd.Cd_id
GROUP BY Shop.Name, Personal.Name
ORDER BY Sales DESC

Or something like this? But how in Rep.Services???

...LEFT OUTER JOIN (
SELECT P.work_id, P.Name, SUM(C.Price) AS TotalSale
FROM @Personal P
INNER JOIN @Purchase B
ON B.Salesperson_id = P.Personal_id
INNER JOIN @Cd C
ON C.Cd_id = B.Cd_id
GROUP BY P.Work_id, P.Name
) D
ON D.Work_id = S.Shop_id