Assessment of third-party income: seized books transferred to relevant officer who may assess or reassess income under specified provisions. Where seized or requisitioned valuables or books of account relate to a person other than the searched person, they must be handed to the Assessing Officer having jurisdiction over that other person, who may then issue notice and assess or reassess that other person's total income under the search-related assessment provisions for the relevant year(s) and for the six assessment years immediately preceding the relevant assessment year if the seized materials bear on determination of that income.