Which case is cited as the business purpose doctrine: Gregory v. Helvering or Ableman v. Booth?
Gregory v. Helvering: Gregory v. Helvering, 293 U.S. 465 (1935), was a landmark decision by the United States Supreme Court concerned with U.S. income tax law. Gregory v. Helvering:  The case is cited as part of the basis for two legal doctrines: the business purpose doctrine and the doctrine of substance over form. Ableman v. Booth: Ableman v. Booth, 62 U.S. 506 (1859) , was a United States Supreme Court case in which the Court held that State courts cannot issue rulings on federal law that contradict the decisions of federal courts, overturning a decision by the Supreme Court of Wisconsin.
i don't know