a) A beneficiary shall declare the amount of any payment and allowances received by him and/or his spouse with respect to his family situation or to his children from sources other than the Fund. Depending on their nature, they shall be deducted from the corresponding benefits payable under the present Rules.
   b) In the case of spouses who both are beneficiaries of a pension, family and children's allowances for which they may be eligible, shall be payable only to the spouse whose entitlement results in the higher of the two amounts.