Don't need one. Obama's father was a British subject. That means Barack Obama is not a natural born citizen by the criteria in place at the time the Constitution was drafted and ratified.
His mother was...
The phrase, “natural born citizen,” as used in the Constitution to establish criteria for holding the office of President, has a specific, historical and restrictive meaning, and it has not been excised by amendment or altered by findings of the Supreme Court, which, in any case, has not authority to do so.
Bottom line: Barack Hussein Obama is not qualified to hold the office to which he has been mistakenly elected.