Section 5 in THE CONSTITUTION (FORTY-SIXTH AMENDMENT) ACT, 1982
5. The various problems connected with the power of the States to levy a tax on the sale of goods and with the Central Sales Tax Act, 1956 were referred to the Law Commission of India. The Commission considered these matters in their Sixty-first Report and, recommended, inter alia, certain amendments in the Constitution if as a matter of administrative policy it is decided to levy tax on transactions of the nature mentioned in the preceding paragraphs.
