ARTICLE 21
Professors and Researchers
(1) An individual who visits a Contracting State for the purpose of teaching or carrying out research at a university, college or other officially recognized educational or research institution in that Contracting State and who is or was immediately before the visit a resident of the other Contracting State, shall be exempt from taxation in the first-mentioned Contracting State on remuneration for such teaching or research for a period not exceeding two years from the date of his first visit for that purpose.
(2) The provisions of paragraph (1) shall not apply to income from research if such research is undertaken not in the public interest but primarily for the private benefit of a specific person or persons.