Rule 38.5.166 - WORKING PAPERS - EXPENSE CHARGED OTHER THAN PRESCRIBED DEPRECIATION, DEPLETION AND AMORTIZATION(1) Working papers shall be included in support of Statement I as a reconciliation of the aggregate investment in utility plant shown in Statement C, and the expense thereon charged in the first instance to other than prescribed depreciation, depletion, and amortization expense accounts.Sec. 69-3-103, MCA; IMP, Sec. 69-2-101, MCA;