“Professional journalist” means a person regularly engaged in collecting, photographing, recording, writing, editing, reporting, or publishing news, for gain or livelihood, who obtained the information sought while working as a salaried employee of, or independent contractor for, a newspaper, news journal, news agency, press association, wire service, radio or television station, network, or news magazine. Book authors and others who are not professional journalists, as defined in this paragraph, are not included in the provisions of this section.