Dismissing the appeal of the assessee the Court held that S.11(4A) obliges an institution which seeks to have benefit of S. 11 if it carries on business incidental to its business objects, to maintain separate books of account . Since exhibition organized by assessee was a well-organised and regular activity incidental to business of assessee but no separate books of account were maintained for purposes of carrying out said exhibition and, thus, requirement of maintaining separate books of account was not satisfied accordingly the assessee was not entitled to exemption. (AY. 1992-93)