Payments Received by Professors, Teachers and Research Scholars
(1) A professor or teacher who is, or was a resident of the Contracting State immediately before visiting the other Contracting State for the purpose of teaching or engaging in research, or both, at university, college, school or other approved institution in that other Contracting State shall be exempt from tax in that other State on any remuneration for such teaching or research for a period not exceeding two years from the date of his arrival in that other State.
(2) This Article shall not apply to income from research, if such research is undertaken primarily for the private benefit of a specific person or persons.
(3) For the purposes of this Article and Article 20, an individual shall be deemed to be a resident of a Contracting State if he is resident in that State or in the immediately preceding fiscal year.
(4) For the purposes of paragraph (1), "approved institution" means an institution which has been approved in this regard by the competent authority of the concerned Contracting State.