(1) When a person in the business of broadcasting film or radio programming, whether through the public airwaves, by cable, direct or indirect satellite transmission or any other means of communication, either through a network (including owned and affiliated stations) or through an affiliated, unaffiliated, or independent television or radio broadcasting station, has income from sources both within and outside Montana, the amount of business income from sources within Montana shall be determined pursuant to Title 15, chapter 31, part 3, MCA, and the supporting Administrative Rules OF MONTANA, except as modified by this rule.