ARTICLE 14
Independent Personal Services
(1) Income derived by a resident of a Contracting State from professional services or other activities of an independent nature, shall be taxable only in that State unless that resident does not have a fixed base regularly available to him in the other Contracting State for the purpose of performing his activities. If he has such a fixed base, the income shall be taxable in that other State, but only so much of them as are attributable to the activities carried on through that fixed base
(2) The term "professional services" includes, in particular, independent scientific, literary, artistic, educational or teaching activities as well as the independent activities of physicians, lawyers, engineers, architects, dentists and accountants.