Artikel 20

1. Payments which a teacher or researcher who is a resident of a Contracting State and who is present in the other Contracting State at the invitation of the Government of that other Contracting State or of a university, college, school, museum or other cultural institution in that other Contracting State or under an official program of cultural exchange, is present in that other Contracting State for a period not exceeding three consecutive years solely for the purpose of teaching, giving lectures or carrying out research at such institution receives, shall be exempted from tax in that other Contracting State on his remuneration for such activity.
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 primarily for the private benefit of a specific person or persons.