Research expenditure deduction: failure to file completion certificate enables recomputation of taxable income. Where an assessee claimed a deduction for expenditure on scientific research but fails to furnish a completion certificate from the prescribed authority within one year of the period allowed for completion, the excess deduction shall be deemed wrongly made and the tax officer may recompute the assessee's total income for the relevant previous year; the general assessment-amendment procedure applies, with the limitation period to be reckoned from the end of the previous year in which the prescribed authority's completion period expired.