Permanent establishment profit attribution limits taxation to income attributable to local activity, not total contract receipts. The Protocol prescribes that the construction-period time limit in Article 5 begins when construction activity itself begins, excluding preparatory time, and that Article 7 requires profits of a permanent establishment to be determined only on income attributable to the permanent establishment's actual activity in the source State rather than on the enterprise's total contract receipts; head office profits remain taxable only in the resident State.