State taxation of employees in interstate commerce : hearing before the Committee on Commerce, United States Senate, Eighty-eighth Congress, second session, on S. 1719, a bill to amend the Interstate commerce act and the Federal aviation act of 1958 in order to exempt certain wages and salary of employees from withholding for tax purposes under the laws of states or subdivisions thereof other than the state or subdivision of the employee's residence. February 24, 1964.