Tax relief in relation to export turnover.—Omitted by the Finance Act, 1983 (11 of 1983), s. 33 (w.e.f. 1-4-1983). The provisions of this section were later substituted by scheme contained in section 80HHC, inserted by the Finance Act, 1983 (11 of 1983), s. 24 (w.e.f. 1-4-1983). Originally section 89A was inserted by the Finance Act, 1982 (29 of 1983), s. 22 (w.e.f. 1-6-1982).