Please show the credit card number of David Bradley.
credit card number refers to CardNumber;
SELECT T3.CardNumber FROM Person AS T1 INNER JOIN PersonCreditCard AS T2 ON T1.BusinessEntityID = T2.BusinessEntityID INNER JOIN CreditCard AS T3 ON T2.CreditCardID = T3.CreditCardID WHERE T1.FirstName = 'David' AND T1.LastName = 'Bradley'