Regulations Governing Application of Agreements for the Avoidance of Double Taxation with Respect to Taxes on Income Article 19

The determination of the source State referred to in the preceding article shall be governed by the provisions of the DTA; where matters are not provided for in the DTA, the stipulations of the Income Tax Act or relevant provisions of other laws and regulations shall govern.
中文原文 適用所得稅協定查核準則第19條
前條所得來源地之認定,所得稅協定有規定者,依其規定;其無規定者,依所得稅法及相關法令規定認定。

English translation for reference only; the Chinese text prevails. Not legal advice.