List the carriers of devices that have no devices in stock.
SELECT Carrier FROM device WHERE Device_ID NOT IN (SELECT Device_ID FROM stock)
SELECT Carrier FROM device WHERE Device_ID NOT IN (SELECT Device_ID FROM stock)
[{'Carrier': 'MTS Mobility'}, {'Carrier': 'Verizon Wireless'}, {'Carrier': 'Telus Mobility'}, {'Carrier': 'Iusacell'}]