Find and list the full name and email of the customers who used American Express cards in Sac State Union.
full name = First, Last; American Express cards refers to CreditCardType = 'American Express'; Sac State Union refers to LocationName = 'Sac State Union';
SELECT DISTINCT T1.First, T1.Last, T1.Email FROM customers AS T1 INNER JOIN `transaction` AS T2 ON T1.CustomerID = T2.CustomerID INNER JOIN location AS T3 ON T2.LocationID = T3.LocationID WHERE T3.LocationName = 'Sac State Union' AND T2.CreditCardType = 'American Express'