ARM 42.26.1002. GENERAL RULE

(1) Except as specifically modified by this rule, when a person in the business of publishing, selling, licensing, or distributing newspapers, magazines, periodicals, trade journals, or other printed material has income from sources both within and outside of Montana, the amount of business income from sources within Montana from such business activity shall be determined pursuant to Title 15, chapter 31, part 3, MCA, and the supporting administrative rules.