An individual who is or was a resident of a Contracting State immediately before making a visit to the other Contracting State, and who, at the invitation of any university, college, school or other similar educational institution, which is recognised by the competent authority in that other Contracting State visits that other Contracting State for a period not exceeding two years solely for the purpose of teaching or research or both at such educational institution shall be exempt from tax in that other Contracting State on his remuneration for such teaching or research.