Cal. Rev. & Tax. Code § 25101.1

The amendments made at the 1957 Regular Session of the Legislature to Section 25101 of the Revenue and Taxation Code shall be applicable only with respect to income years beginning after December 31, 1956. The determination as to whether income derived from or attributable to transportation by sea or air is allocable to or taxable by California for any income year beginning before January 1, 1957, shall be made as if Section 25101 had not been amended at the 1957 Regular Session of the Legislature and without inferences drawn from the fact that such amendments were not expressly made applicable with respect to income years beginning before January 1, 1957.