ARTICLE 14
Independent Personal Services
(1) Income derived by an individual who is a resident in the sovereign territory of a Contracting Party in respect of professional services or other activities of an independent character shall be taxable only in the sovereign territory of that Contracting Party unless he has a fixed base regularly available to him in the sovereign territory of the other Contracting Party for the purpose of performing his activities. If he has such a fixed base, the income may be taxed in the sovereign territory of the other Contracting Party but only so much of it as is attributable to that fixed base.
(2) The term "professional services" includes especially independent scientific, literary, artistic, educational or teaching activities as well as the independent activities of physicians, dentists, lawyers, engineers, architects and accountants.