Inspection powers compel production of business records and permit retention, copying, and questioning to administer VAT law. Section 59 empowers the Commissioner to inspect all records, books of account, registers and other documents of dealers, transporters and warehouse operators; to require dealers and other persons in possession of business-related records to produce documents, answer questions and furnish additional information; to prescribe the manner of production and verification; and to retain, remove or take copies or extracts of such records without fee for purposes of administering the Act.