Approval under section 35(1)(ii) for research institutions requires separate research accounts, annual returns, audited accounts, and renewal applications. Approval to Environmental Protection Research Foundation, Sangli, under the Income-tax Act for recognized research institutions is conditional on maintaining a separate account for research funds, filing annual returns of scientific research activities by 30th April, submitting audited annual accounts and balance-sheet to the prescribed authority and Commissioner by 30th June, and applying to the Central Board of Direct Taxes three months before approval expiry for extension.