Show the carriers of devices in stock at more than one shop.
SELECT T2.Carrier FROM stock AS T1 JOIN device AS T2 ON T1.Device_ID  =  T2.Device_ID GROUP BY T1.Device_ID HAVING COUNT(*)  >  1
SELECT T2.Carrier FROM stock AS T1 JOIN device AS T2 ON T1.Device_ID  =  T2.Device_ID GROUP BY T1.Device_ID HAVING COUNT(*)  >  1
[{'Carrier': 'Bell Mobility'}, {'Carrier': 'Vodafone AU'}]