CREATE TABLE member (membership_card VARCHAR, address VARCHAR)

What is the membership card held by both members living in Hartford and ones living in Waterbury address?
SELECT membership_card FROM member WHERE address = 'Hartford' INTERSECT SELECT membership_card FROM member WHERE address = 'Waterbury'
SELECT "membership_card" FROM "member" WHERE "address" = 'Hartford' INTERSECT SELECT "membership_card" FROM "member" WHERE "address" = 'Waterbury'