ระบุรหัสพื้นที่ที่ผู้ลงคะแนนโหวตให้ทั้งผู้เข้าแข่งขัน 'Tabatha Gehling' และผู้แข่งขัน 'Kelly Clauss' ไม่จำเป็นที่จะต้องใช้ตารางทั้งหมด
List the area codes in which voters voted both for the contestant 'Tabatha Gehling' and the contestant 'Kelly Clauss'.It is not neccessary to use all the tables.
 votes:  (contestant_number [ VARCHAR ] state [ VARCHAR) ]
SELECT T3.area_code FROM contestants AS T1 JOIN votes AS T2 ON T1.contestant_number = T2.contestant_number JOIN area_code_state AS T3 ON T2.state = T3.state WHERE T1.contestant_name = 'Tabatha Gehling' INTERSECT SELECT T3.area_code FROM contestants AS T1 JOIN votes AS T2 ON T1.contestant_number = T2.contestant_number JOIN area_code_state AS T3 ON T2.state = T3.state WHERE T1.contestant_name = 'Kelly Clauss'