ARTICLE 20
Teachers and Researchers
(1) A professor, teacher or researcher who makes a temporary visit to a Contracting State for the purpose of teaching or conducting research at a university, college, school or other recognized educational institution and who is, or immediately before such visit was, a resident of the other Contracting State shall be exempted from tax in the first-mentioned State for a period not exceeding four years in respect of remuneration for such teaching or research.
(2) This Article shall not apply to remuneration which a professor or teacher receives for conducting research if the research is undertaken primarily for the private benefit of a specific person or persons.