ARTICLE 20
Professors and Teachers
(1) A professor or teacher who makes a temporary visit to a Contracting State for a period not exceeding two years for the purpose of teaching or conducting research at a university, college, school or other educational institution, and who is, or immediately before such visit was, a resident of the other Contracting State shall be exempt from tax in the first-mentioned Contracting State in respect of remuneration for such teaching or research.
(2) The provisions of paragraph 1 of this Article shall not apply to income from research if such research is undertaken not in the public interest, but for the private benefit of a specific person or persons.